Intel Core I5 I5 3320m 2 60 Ghz Processor BX80638I53320M User Manual

®
Mobile 3rd Generation Intel  
Core™ Processor Family  
Specification Update  
September 2013  
Revision 015  
Reference Number: 326770  
Contents  
4
Specification Update  
Revision History  
Revision  
Description  
Date  
001  
Initial Release.  
April 2012  
Added Errata BU69–BU85  
Updated Processor Identification Table  
002  
003  
May 2012  
June 2012  
Added L-1 stepping to Component Identification using Programming  
Added L-1 stepping to errata summary table  
Updated Processor Identification Table  
004  
005  
Added Errata BU86-BU90  
June 2012  
®
Added Mobile 3rd Generation Intel Core™ i7-3940XM, i7-3840QM, i7-3740QM  
processors  
October 2012  
006  
007  
008  
009  
010  
011  
Added Errata BU91-BU94  
Added Errata BU95-BU98  
Documentation Change  
Added Errata BU99, BU100  
Added Errata BU101  
November 2012  
December 2012  
January 2013  
March 2013  
April 2013  
Added Errata BU102, BU103, BU104  
May 2013  
Added Errata BU105, BU106, BU107, BU108  
Made changes to Erratum BU101  
012  
June 2013  
013  
014  
015  
Added Erratum BU109  
Added Errata BU110, BU111  
Added Errata BU112  
July 2013  
August 2013  
September 2013  
Specification Update  
5
 
Preface  
This document is an update to the specifications contained in the Affected Documents  
table below. This document is a compilation of device and documentation errata,  
specification clarifications and changes. It is intended for hardware system  
manufacturers and software developers of applications, operating systems, or tools.  
Information types defined in Nomenclature are consolidated into the specification  
update and are no longer published in other documents.  
This document may also contain information that was not previously published.  
Affected Documents  
Document Title  
Document Number  
®
Mobile 3rd Generation Intel Core™ Processor Family Datasheet, Volume 1  
326768-004  
326769-002  
®
Mobile 3rd Generation Intel Core™ Processor Family Datasheet, Volume 2  
Related Documents  
Document Number/  
Location  
Document Title  
AP-485, Intel® Processor Identification and the CPUID Instruction  
design/processor/  
Intel® 64 and IA-32 Architectures Software Developer’s Manual,  
Volume 1: Basic Architecture  
Intel® 64 and IA-32 Architectures Software Developer’s Manual,  
Volume 2A: Instruction Set Reference Manual A-M  
Intel® 64 and IA-32 Architectures Software Developer’s Manual,  
Volume 2B: Instruction Set Reference Manual N-Z  
Intel® 64 and IA-32 Architectures Software Developer’s Manual,  
Volume 3A: System Programming Guide  
products/processor/  
Intel® 64 and IA-32 Architectures Software Developer’s Manual,  
Volume 3B: System Programming Guide  
Intel® 64 and IA-32 Intel Architecture Optimization Reference  
Manual  
design/processor/  
Intel® 64 and IA-32 Architectures Software Developer’s Manual  
Documentation Changes  
ACPI Specifications  
6
Specification Update  
 
Nomenclature  
Errata are design defects or errors. These may cause the processor behavior to  
deviate from published specifications. Hardware and software designed to be used with  
any given stepping must assume that all errata documented for that stepping are  
present on all devices.  
S-Spec Number is a five-digit code used to identify products. Products are  
differentiated by their unique characteristics such as, core speed, L2 cache size,  
package type, etc. as described in the processor identification information table. Read  
all notes associated with each S-Spec number.  
Specification Changes are modifications to the current published specifications.  
These changes will be incorporated in any new release of the specification.  
Specification Clarifications describe a specification in greater detail or further  
highlight a specification’s impact to a complex design situation. These clarifications will  
be incorporated in any new release of the specification.  
Documentation Changes include typos, errors, or omissions from the current  
published specifications. These will be incorporated in any new release of the  
specification.  
Note:  
Errata remain in the specification update throughout the product’s lifecycle, or until a  
particular stepping is no longer commercially available. Under these circumstances,  
errata removed from the specification update are archived and available upon request.  
Specification changes, specification clarifications and documentation changes are  
removed from the specification update when the appropriate changes are made to the  
appropriate product specification or user documentation (datasheets, manuals, and so  
on).  
Specification Update  
7
Summary Tables of Changes  
The following tables indicate the errata, specification changes, specification  
clarifications, or documentation changes which apply to the processor. Intel may fix  
some of the errata in a future stepping of the component, and account for the other  
outstanding issues through documentation or specification changes as noted. These  
tables uses the following notations:  
Codes Used in Summary Tables  
Stepping  
X:  
Errata exists in the stepping indicated. Specification Change or  
Clarification that applies to this stepping.  
(No mark)  
or (Blank box):  
This erratum is fixed in listed stepping or specification change  
does not apply to listed stepping.  
Page  
(Page):  
Page location of item in this document.  
Status  
Doc:  
Document change or update will be implemented.  
This erratum may be fixed in a future stepping of the product.  
This erratum has been previously fixed.  
Plan Fix:  
Fixed:  
No Fix:  
There are no plans to fix this erratum.  
Row  
Change bar to left of a table row indicates this erratum is either new or modified from  
the previous version of the document.  
Errata (Sheet 1 of 5)  
Steppings  
Number  
Status  
ERRATA  
E-1  
L-1  
BU1  
BU2  
X
X
No Fix  
No Fix  
The Processor May Report a #TS Instead of a #GP Fault  
REP MOVS/STOS Executing with Fast Strings Enabled and Crossing Page Boundaries  
with Inconsistent Memory Types may use an Incorrect Data Size or Lead to Memory-  
Ordering Violations.  
X
X
BU3  
BU4  
BU5  
X
X
X
X
X
X
No Fix  
No Fix  
No Fix  
IO_SMI Indication in SMRAM State Save Area May be Set Incorrectly  
Performance Monitor SSE Retired Instructions May Return Incorrect Values  
IRET under Certain Conditions May Cause an Unexpected Alignment Check Exception  
Performance Monitoring Event FP_MMX_TRANS_TO_MMX May Not Count Some  
Transitions  
BU6  
X
X
No Fix  
8
Specification Update  
 
Errata (Sheet 2 of 5)  
Steppings  
Number  
Status  
ERRATA  
E-1  
L-1  
General Protection Fault (#GP) for Instructions Greater than 15 Bytes May be  
Preempted  
BU7  
BU8  
X
X
No Fix  
No Fix  
LBR, BTS, BTM May Report a Wrong Address when an Exception/Interrupt Occurs in  
64-bit Mode  
X
X
Incorrect Address Computed For Last Byte of FXSAVE/FXRSTOR or XSAVE/XRSTOR  
Image Leads to Partial Memory Update  
BU9  
BU10  
BU11  
X
X
X
X
X
X
No Fix  
No Fix  
No Fix  
Values for LBR/BTS/BTM Will be Incorrect after an Exit from SMM  
EFLAGS Discrepancy on Page Faults and on EPT-Induced VM Exits after a Translation  
Change  
BU12  
BU13  
BU14  
BU15  
BU16  
BU17  
BU18  
BU19  
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
No Fix  
No Fix  
No Fix  
No Fix  
No Fix  
No Fix  
No Fix  
No Fix  
B0-B3 Bits in DR6 For Non-Enabled Breakpoints May be Incorrectly Set  
MCi_Status Overflow Bit May Be Incorrectly Set on a Single Instance of a DTLB Error  
Debug Exception Flags DR6.B0-B3 Flags May be Incorrect for Disabled Breakpoints  
LER MSRs May Be Unreliable  
Storage of PEBS Record Delayed Following Execution of MOV SS or STI  
PEBS Record not Updated when in Probe Mode  
MONITOR or CLFLUSH on the Local XAPIC's Address Space Results in Hang  
Faulting MMX Instruction May Incorrectly Update x87 FPU Tag Word  
An Uncorrectable Error Logged in IA32_CR_MC2_STATUS May also Result in a  
System Hang  
BU20  
BU21  
X
X
X
X
No Fix  
No Fix  
#GP on Segment Selector Descriptor that Straddles Canonical Boundary May Not  
Provide Correct Exception Error Code  
DR6.B0-B3 May Not Report All Breakpoints Matched When a MOV/POP SS is  
Followed by a Store or an MMX Instruction  
BU22  
BU23  
BU24  
X
X
X
X
X
X
No Fix  
No Fix  
No Fix  
APIC Error “Received Illegal Vector” May be Lost  
Changing the Memory Type for an In-Use Page Translation May Lead to Memory-  
Ordering Violations  
Reported Memory Type May Not Be Used to Access the VMCS and Referenced Data  
Structures  
BU25  
BU26  
BU27  
BU28  
X
X
X
X
X
X
X
X
No Fix  
No Fix  
No Fix  
No Fix  
LBR, BTM or BTS Records May have Incorrect Branch From Information After an EIST/  
T-state/S-state/C1E Transition or Adaptive Thermal Throttling  
Fault Not Reported When Setting Reserved Bits of Intel® VT-d Queued Invalidation  
Descriptors  
FP Data Operand Pointer May Be Incorrectly Calculated After an FP Access Which  
Wraps a 4-Gbyte Boundary in Code That Uses 32-Bit Address Size in 64-bit Mode  
VMREAD/VMWRITE Instruction May Not Fail When Accessing an Unsupported Field in  
VMCS  
BU29  
BU30  
BU31  
X
X
X
X
X
X
No Fix  
No Fix  
No Fix  
Spurious Interrupts May be Generated From the Intel® VT-d Remap Engine  
Malformed PCIe Transactions May be Treated as Unsupported Requests Instead of as  
Critical Errors  
Reception of Certain Malformed Transactions May Cause PCIe Port to Hang Rather  
Than Reporting an Error  
BU32  
BU33  
X
X
X
X
No Fix  
No Fix  
Clock Modulation Duty Cycle Cannot be Programmed to 6.25%  
Specification Update  
9
Errata (Sheet 3 of 5)  
Steppings  
Number  
Status  
ERRATA  
E-1  
L-1  
BU34  
BU35  
X
X
X
X
No Fix  
No Fix  
Processor May Fail to Acknowledge a TLP Request  
An Unexpected PMI May Occur After Writing a Large Value to IA32_FIXED_CTR2  
A Write to the IA32_FIXED_CTR1 MSR May Result in Incorrect Value in Certain  
Conditions  
BU36  
X
X
No Fix  
BU37  
BU38  
X
X
X
X
No Fix  
No Fix  
PCIe* LTR Incorrectly Reported as Being Supported  
PerfMon Overflow Status Can Not be Cleared After Certain Conditions Have Occurred  
#GP May be Signaled When Invalid VEX Prefix Precedes Conditional Branch  
Instructions  
BU39  
X
X
No Fix  
BU40  
BU41  
X
X
X
X
No Fix  
No Fix  
Interrupt From Local APIC Timer May Not Be Detectable While Being Delivered  
PCI Express* Differential Peak-Peak Tx Voltage Swing May Violate the Specification  
PCMPESTRI, PCMPESTRM, VPCMPESTRI and VPCMPESTRM Always Operate with  
32-bit Length Registers  
BU42  
X
X
No Fix  
BU43  
BU44  
X
X
X
X
No Fix  
No Fix  
Multiple Performance Monitor Interrupts are Possible on Overflow of Fixed Counter 0  
IA32_FEATURE_CONTROL MSR May be Uninitialized on a Cold Reset  
DR6.B0-B3 May Not Report All Breakpoints Matched When a MOV/POP SS is  
Followed by a REP MOVSB or STOSB  
BU45  
X
X
No Fix  
Setting Hardware Autonomous Speed Disable Configuration Bit Will Block Initial Speed  
Upgrade  
BU46  
BU47  
BU48  
X
X
X
X
X
X
No Fix  
No Fix  
No Fix  
LTR Message is Not Treated as an Unsupported Request  
64-bit REP MOVSB/STOSB May Clear The Upper 32-bits of RCX, RDI And RSI Before  
Any Data is Transferred  
An Interrupt Recognized Prior to First Iteration of REP MOVSB/STOSB May Result  
EFLAGS.RF Being Incorrectly Set  
BU49  
BU50  
X
X
X
X
No Fix  
No Fix  
Accessing Physical Memory Space 0-640K through the Graphics Aperture May Cause  
Unpredictable System Behavior  
BU51  
BU52  
BU53  
BU54  
X
X
X
X
X
X
X
X
No Fix  
No Fix  
No Fix  
No Fix  
PEBS May Unexpectedly Signal a PMI After The PEBS Buffer is Full  
Instructions Retired Event May Over Count Execution of IRET Instructions  
PCIe* Link May Unexpectedly Exit Loopback State  
The RDRAND Instruction Will Not Execute as Expected  
A PCIe* Device That Initially Transmits Minimal Posted Data Credits May Cause a  
System Hang  
BU55  
X
X
No Fix  
BU56  
BU57  
X
X
X
X
No Fix  
No Fix  
PCI Express* Gen3 Receiver Return Loss May Exceed Specifications  
Direct Access Via VT-d to The Processor Graphics Device May Lead to a System Hang  
An Event May Intervene Before a System Management Interrupt That Results from IN  
or INS  
BU58  
BU59  
X
X
X
X
No Fix  
No Fix  
PCIe* May Associate Lanes That Are Not Part of Initial Link Training to L0 During  
Upconfiguration  
The Processor May Not Comply With PCIe* Equalization Preset Reflection  
Requirements for 8 GT/s Mode of Operation  
BU60  
BU61  
BU62  
X
X
X
X
X
X
No Fix  
No Fix  
No Fix  
Processor May Issue PCIe* EIEOS at Incorrect Rate  
Reduced Swing Output Mode Needs Zero De-emphasis to be Supported in PCIe* 5GT/  
s Speed  
10  
Specification Update  
Errata (Sheet 4 of 5)  
Steppings  
Number  
Status  
ERRATA  
E-1  
L-1  
PCIe* Root-port Initiated Compliance State Transmitter Equalization Settings May be  
Incorrect  
BU63  
BU64  
BU65  
X
X
X
X
X
X
No Fix  
No Fix  
No Fix  
PCIe* Controller May Incorrectly Log Errors on Transition to RxL0s  
Reception of Certain Malformed Transactions May Cause PCIe* Port to Hang Rather  
Than Reporting an Error  
BU66  
BU67  
BU68  
BU69  
X
X
X
X
X
X
X
X
No Fix  
No Fix  
No Fix  
No Fix  
PCIe* Link Width May Degrade After a Warm Reset  
MSR_PKG_Cx_RESIDENCY MSRs May Not be Accurate  
Execution of Package C7 May Result in a Hang  
PCIe* Link May Not Enter Loopback.Active When Directed  
Execution of VAESIMC or VAESKEYGENASSIST With An Illegal Value for VEX.vvvv  
May Produce a #NM Exception  
BU70  
X
X
No Fix  
BU71  
BU72  
BU73  
X
X
X
X
X
X
No Fix  
No Fix  
No Fix  
Unexpected #UD on VZEROALL/VZEROUPPER  
PCIe* Root Port May Not Initiate Link Speed Change  
Successive Fixed Counter Overflows May be Discarded  
Execution of FXSAVE or FXRSTOR With the VEX Prefix May Produce a #NM  
Exception  
BU74  
BU75  
BU76  
X
X
X
X
X
X
No Fix  
No Fix  
No Fix  
VM Exits Due to “NMI-Window Exiting” May Not Occur Following a VM Entry to the  
Shutdown State  
Execution of INVVPID Outside 64-Bit Mode Cannot Invalidate Translations For 64-Bit  
Linear Addresses  
BU77  
BU78  
BU79  
BU80  
BU81  
BU82  
BU83  
X
X
X
X
X
X
X
X
X
X
X
X
X
X
No Fix  
No Fix  
No Fix  
No Fix  
No Fix  
No Fix  
No Fix  
PCIe* Controller May Not Properly Indicate Link Electrical Idle Condition  
PCIe* Controller May Not Enter Loopback  
Link Margin Characterization May Hang Link  
Unused PCIe* Lanes May Report Correctable Errors  
RDMSR of IA32_PERFEVTSEL{4-7} May Return Erroneous Information  
PCIe* Link May Fail Link Width Upconfiguration  
Graphics L3 Cache Parity Errors May Not be Detected  
A PCIe* Link That is in Link Disable State May Prevent DDR I/O Buffers From Entering  
a Power Gated State  
BU84  
X
X
No Fix  
BU85  
BU86  
BU87  
BU88  
BU89  
X
X
X
X
X
X
X
No Fix  
No Fix  
No Fix  
No Fix  
No Fix  
Graphics L3 Cache Redundancy May Not Behave as Expected  
REP MOVSB May Incorrectly Update ECX, ESI, and EDI  
Performance-Counter Overflow Indication May Cause Undesired Behavior  
RDMSR of IA32_PERFEVTSEL4-7 May Return an Incorrect Result  
VEX.L is Not Ignored with VCVT*2SI Instructions  
X
X
XX  
Intel® Turbo Boost Technology May be Incorrectly Reported as Supported on Intel®  
Core™ i3-3217U  
BU90  
X
X
No Fix  
BU91  
BU92  
X
X
X
X
No Fix  
No Fix  
Concurrently Changing the Memory Type and Page Size May Lead to a System Hang  
MCI_ADDR May be Incorrect For Cache Parity Errors  
During Package Power States Repeated PCIe* and/or DMI L1 Transitions May Cause a  
System Hang  
BU93  
X
X
No Fix  
Specification Update  
11  
Errata (Sheet 5 of 5)  
Steppings  
Number  
Status  
ERRATA  
E-1  
L-1  
Instruction Fetches Page-Table Walks May be Made Speculatively to Uncacheable  
Memory  
BU94  
X
X
No Fix  
BU95  
BU96  
X
X
X
X
No Fix  
No Fix  
The Processor May Not Properly Execute Code Modified Using A Floating-Point Store  
Execution of GETSEC[SEXIT] May Cause a Debug Exception to be Lost  
VM Exits Due to GETSEC May Save an Incorrect Value for “Blocking by STI” in the  
Context of Probe-Mode Redirection  
BU97  
X
X
No Fix  
Specific Graphics Blitter Instructions May Result in Unpredictable Graphics Controller  
Behavior  
BU98  
BU99  
X
X
X
X
X
X
X
X
X
X
No Fix  
No Fix  
No Fix  
No Fix  
No Fix  
IA32_MC5_CTL2 is Not Cleared by a Warm Reset  
CPUID Instruction May Not Report the Processor Number in the Brand String for Intel®  
Core™ i3-3227U and i5-3337U Processors.  
BU100  
BU101  
BU102  
Performance Monitor Counters May Produce Incorrect Results  
The Corrected Error Count Overflow Bit in IA32_ MC0_STATUS is Not Updated After a  
UC Error is Logged  
BU103  
BU104  
X
X
X
X
No Fix  
No Fix  
Spurious VT-d Interrupts May Occur When the PFO Bit is Set  
Processor May Livelock During On Demand Clock Modulation  
IA32_VMX_VMCS_ENUM MSR (48AH) Does Not Properly Report The Highest Index  
Value Used For VMCS Encoding  
BU105  
X
X
No Fix  
BU106  
BU107  
X
X
X
X
No Fix  
No Fix  
The Upper 32 Bits of CR3 May be Incorrectly Used With 32-Bit Paging  
EPT Violations May Report Bits 11:0 of Guest Linear Address Incorrectly  
IA32_VMX_VMCS_ENUM MSR (48AH) Does Not Properly Report The Highest Index  
Value Used For VMCS Encoding  
BU108  
BU109  
X
X
X
X
No Fix  
No Fix  
DMA Remapping Faults for the Graphics VT-d Unit May Not Properly Report Type of  
Faulted Request  
BU110  
BU111  
X
X
X
X
No Fix  
No Fix  
Intel® Trusted Execution Technology ACM Authentication Failure  
Virtual-APIC Page Accesses With 32-Bit PAE Paging May Cause a System Crash  
Address Translation Faults for Intel® VT-d May Not be Reported for Display Engine  
Memory Accesses  
BU112  
X
X
No Fix  
Specification Changes  
Number  
SPECIFICATION CHANGES  
None for this revision of this specification update.  
Specification Clarifications  
Number  
SPECIFICATION CLARIFICATIONS  
None for this revision of this specification update.  
Documentation Changes  
Number  
DOCUMENTATION CHANGES  
BU1  
On-Demand Clock Modulation Feature Clarification  
12  
Specification Update  
§ §  
Specification Update  
13  
Identification Information  
Component Identification using Programming Interface  
The processor stepping can be identified by the following register contents:  
Extended  
Extended  
Processor  
Family  
Model  
Stepping  
Reserved  
31:28  
Reserved  
15:14  
1
2
3
4
5
6
Family  
Model  
Type  
Code  
Number  
ID  
27:20  
19:16  
13:12  
11:8  
7:4  
3:0  
00000000b  
0011b  
00b  
0110  
1010b  
xxxxb  
Notes:  
1.  
The Extended Family, bits [27:20] are used in conjunction with the Family Code, specified in bits [11:8],  
to indicate whether the processor belongs to the Intel386, Intel486, Pentium, Pentium Pro, Pentium 4,  
®
or Intel Core™ processor family.  
2.  
3.  
The Extended Model, bits [19:16] in conjunction with the Model Number, specified in bits [7:4], are  
used to identify the model of the processor within the processor’s family.  
The Processor Type, specified in bits [13:12] indicates whether the processor is an original OEM  
processor, an OverDrive processor, or a dual processor (capable of being used in a dual processor  
system).  
4.  
5.  
6.  
The Family Code corresponds to bits [11:8] of the EDX register after RESET, bits [11:8] of the EAX  
register after the CPUID instruction is executed with a 1 in the EAX register, and the generation field of  
the Device ID register accessible through Boundary Scan.  
The Model Number corresponds to bits [7:4] of the EDX register after RESET, bits [7:4] of the EAX  
register after the CPUID instruction is executed with a 1 in the EAX register, and the model field of the  
Device ID register accessible through Boundary Scan.  
The Stepping ID in bits [3:0] indicates the revision number of that model. See Table 1 for the processor  
stepping ID number in the CPUID information.  
When EAX is initialized to a value of ‘1, the CPUID instruction returns the Extended  
Family, Extended Model, Processor Type, Family Code, Model Number and Stepping ID  
value in the EAX register. Note that the EDX processor signature value after reset is  
equivalent to the processor signature output value in the EAX register.  
Cache and TLB descriptor parameters are provided in the EAX, EBX, ECX and EDX  
registers after the CPUID instruction is executed with a 2 in the EAX register.  
The processor can be identified by the following register contents:  
Processor Graphics  
1
2
4
Stepping  
Vendor ID  
Host Device ID  
Revision ID  
3
Device ID  
E-1  
L-1  
8086h  
8086h  
0154h  
0154h  
0166h  
0166h  
09h  
09h  
Notes:  
1.  
The Vendor ID corresponds to bits 15:0 of the Vendor ID Register located at offset 00h–01h in the PCI  
function 0 configuration space.  
2.  
3.  
4.  
The Host Device ID corresponds to bits 15:0 of the Device ID Register located at Device 0 offset 02h–  
03h in the PCI function 0 configuration space.  
The Processor Graphics Device ID (DID2) corresponds to bits 15:0 of the Device ID Register located at  
Device 2 offset 02h–03h in the PCI function 0 configuration space.  
The Revision Number corresponds to bits 7:0 of the Revision ID Register located at offset 08h in the PCI  
function 0 configuration space.  
14  
Specification Update  
 
Component Marking Information  
The processor stepping can be identified by the following component markings.  
Table 1.  
Processor Identification (Sheet 1 of 6)  
Core Frequency  
(GHz) /  
DDR3 (MHz) /  
Processor  
®
Max Intel  
Turbo Boost  
Technology  
2.0 Frequency  
Shared  
L3 Cache  
Size (MB)  
Processor  
Number  
Processor  
Signature  
Number  
Stepping  
Notes  
Graphics  
Frequency  
1
(GHz)  
3/4 core: 3.6  
2 core: 3.7  
1 core: 3.8  
SR0T2  
SR0MJ  
SR0MK  
SR0ML  
SR0MM  
SR0MN  
SR0MP  
SR0MQ  
SR0MR  
i7-3920XM  
i7-3820QM  
i7-3820QM  
i7-3720QM  
i7-3720QM  
i7-3610QM  
i7-3615QM  
i7-3612QM  
i7-3612QM  
E-1  
E-1  
E-1  
E-1  
E-1  
E-1  
E-1  
E-1  
E-1  
000306A9h  
000306A9h  
000306A9h  
000306A9h  
000306A9h  
000306A9h  
000306A9h  
000306A9h  
000306A9h  
2.9 / 1600 / 650  
2.7 / 1600 / 650  
2.7 / 1600 / 650  
2.6 / 1600 / 650  
2.6 / 1600 / 650  
2.3 / 1600 / 650  
2.3 / 1600 / 650  
2.1 / 1600 / 650  
2.1 / 1600 / 650  
8
8
8
6
6
6
6
6
6
2,3,4,5,6  
2,3,4,5,6  
2,3,4,5,6  
2,3,4,5,6  
2,3,4,5,6  
2,4,6  
3/4 core: 3.5  
2 core: 3.6  
1 core: 3.7  
3/4 core: 3.5  
2 core: 3.6  
1 core: 3.7  
3/4 core: 3.4  
2 core: 3.5  
1 core: 3.6  
3/4 core: 3.4  
2 core: 3.5  
1 core: 3.6  
3/4 core: 3.1  
2 core: 3.2  
1 core: 3.3  
3/4 core: 3.1  
2 core: 3.2  
1 core: 3.3  
2,4,5,6  
2,4,6  
3/4 core: 2.8  
2 core: 3  
1 core: 3.1  
3/4 core: 2.8  
2 core: 3  
2,4,5,6  
1 core: 3.1  
4 core: 0  
3 core: 0  
2 core: 3.4  
1 core: 3.6  
SR0MT  
SR0MU  
SR0MV  
SR0MW  
i7-3520M  
i7-3520M  
i5-3360M  
i5-3360M  
L-1  
L-1  
L-1  
L-1  
000306A9h  
000306A9h  
000306A9h  
000306A9h  
2.9 / 1600 / 650  
2.9 / 1600 / 650  
2.8 / 1600 / 650  
2.8 / 1600 / 650  
4
4
3
3
2,3,4,5,6  
2,3,4,5,6  
2,3,4,5,6  
2,3,4,5,6  
4 core: 0  
3 core: 0  
2 core: 3.4  
1 core: 3.6  
4 core: 0  
3 core: 0  
2 core: 3.3  
1 core: 3.5  
4 core: 0  
3 core: 0  
2 core: 3.3  
1 core: 3.5  
Specification Update  
15  
Table 1.  
Processor Identification (Sheet 2 of 6)  
Core Frequency  
(GHz) /  
DDR3 (MHz) /  
Processor  
Graphics  
®
Max Intel  
Turbo Boost  
Technology  
2.0 Frequency  
Shared  
L3 Cache  
Size (MB)  
Processor  
Number  
Processor  
Signature  
Number  
Stepping  
Notes  
1
(GHz)  
Frequency  
4 core: 0  
3 core: 0  
2 core: 3.1  
1 core: 3.3  
SR0MX  
SR0MY  
SR0MZ  
SR0N0  
SR0N1  
SR0N2  
SR0N5  
SR0N6  
SR0N7  
SR0N8  
SR0N9  
i5-3320M  
i5-3320M  
i5-3210M  
i5-3210M  
i3-3110M  
i3-3110M  
i7-3667U  
i7-3517U  
i5-3427U  
i5-3317U  
i3-3217U  
L-1  
L-1  
L-1  
L-1  
L-1  
L-1  
L-1  
L-1  
L-1  
L-1  
L-1  
000306A9h  
000306A9h  
000306A9h  
000306A9h  
000306A9h  
000306A9h  
000306A9h  
000306A9h  
000306A9h  
000306A9h  
000306A9h  
2.6 / 1600 / 650  
2.6 / 1600 / 650  
2.5 / 1600 / 650  
2.5 / 1600 / 650  
2.4 / 1600 / 650  
2.4 / 1600 / 650  
2 / 1600 / 350  
3
3
3
3
3
3
4
4
3
3
3
2,3,4,5,6  
2,3,4,5,6  
2,4,6  
4 core: 0  
3 core: 0  
2 core: 3.1  
1 core: 3.3  
4 core: 0  
3 core: 0  
2 core: 2.9  
1 core: 3.1  
4 core: 0  
3 core: 0  
2 core: 2.9  
1 core: 3.1  
2,4,5,6  
2,4  
4 core: 0  
3 core: 0  
2 core: 0  
1 core: 2.4  
4 core: 0  
3 core: 0  
2 core: 0  
1 core: 2.4  
2,4  
4 core: 0  
3 core: 0  
2 core: 3  
1 core: 3.2  
2,3,4,5,6  
2,4,5,6  
2,3,4,5,6  
2,4,5,6  
2,4  
4 core: 0  
3 core: 0  
2 core: 2.8  
1 core: 3  
1.9 / 1600 / 350  
1.8 / 1600 / 350  
1.7 / 1600 / 350  
1.8 / 1600 / 350  
4 core: 0  
3 core: 0  
2 core: 2.6  
1 core: 2.8  
4 core: 0  
3 core: 0  
2 core: 2.4  
1 core: 2.6  
4 core: 0  
3 core: 0  
2 core: 0  
1 core: 0  
2 core: 3.5  
1 core: 3.7  
SR0X6  
SR0X8  
i7-3540M  
i7-3540M  
L-1  
L-1  
000306A9h  
000306A9h  
3.0 / 1600 / 1300  
3.0 / 1600 / 1300  
4
4
2,3,4,5,6  
2,3,4,5,6  
2 core: 3.5  
1 core: 3.7  
16  
Specification Update  
Table 1.  
Processor Identification (Sheet 3 of 6)  
Core Frequency  
(GHz) /  
DDR3 (MHz) /  
Processor  
Graphics  
®
Max Intel  
Turbo Boost  
Technology  
2.0 Frequency  
Shared  
L3 Cache  
Size (MB)  
Processor  
Number  
Processor  
Signature  
Number  
Stepping  
Notes  
1
(GHz)  
Frequency  
2 core: 3.4  
1 core: 3.6  
SR0X7  
SR0X9  
SR0XA  
SR0XB  
SR0WY  
SR0WX  
SR0XD  
SR0XC  
SR0XH  
SR0XG  
SR0XE  
SR0XL  
SR0XF  
i5-3380M  
i5-3380M  
i5-3340M  
i5-3340M  
i5-3230M  
i5-3230M  
i3-3130M  
i3-3130M  
i7-3687U  
i7-3537U  
i5-3437U  
i5-3337U  
i3-3227U  
L-1  
L-1  
L-1  
L-1  
L-1  
L-1  
L-1  
L-1  
L-1  
L-1  
L-1  
L-1  
L-1  
000306A9h  
000306A9h  
000306A9h  
000306A9h  
000306A9h  
000306A9h  
000306A9h  
000306A9h  
000306A9h  
000306A9h  
000306A9h  
000306A9h  
000306A9h  
2.9 /1600 /650  
2.9 /1600 /650  
2.7 / 1600 /650  
2.7 / 1600 /650  
2.6 / 1600 / 650  
2.6 / 1600 / 650  
2.6 / 1600 / 650  
2.6 / 1600 / 650  
2.1 /1600 /350  
2 / 1600/ 350  
3
3
3
3
3
3
3
3
4
4
3
3
3
2,3,4,5,6  
2,3,4,5,6  
2,3,4,5,6  
2,3,4,5,6  
2,4,5,6  
2,4,5,6  
2,4  
2 core: 3.4  
1 core: 3.6  
2 core: 3.2  
1 core: 3.4  
2 core: 3.2  
1 core: 3.4  
2 core: 3.0  
1 core: 3.2  
2 core: 3.0  
1 core: 3.2  
2 core:  
1 core: 2.6  
2 core:  
1 core: 2.6  
2,4  
2 core: 3.1  
1 core: 3.3  
2,3,4,5,6  
2,4,5,6  
2,3,4,5,6  
2,4,5,6  
2,4,7  
2 core: 2.9  
1 core: 3.1  
2 core: 2.7  
1 core: 2.9  
1.9 / 1600 / 350  
1.8 / 1600 / 350  
1.9 / 1600 / 350  
2 core: 2.5  
1 core: 2.7  
2 core: N/A  
1 core: 1.9  
4 core: 3.7  
3 core: 3.8  
2 core: 3.9  
1 core: 3.9  
SR0US  
SR0UT  
SR0UV  
i7-3940XM  
i7-3840QM  
i7-3740QM  
E-1  
E-1  
E-1  
000306A9h  
000306A9h  
000306A9h  
3.0 / 1200 / 650  
2.8 / 1200 / 650  
2.7 / 1200 / 650  
8
8
6
1,2,3,4,5,6  
1,2,3,4,5,6  
1,2,3,4,5,6  
4 core: 3.6  
3 core: 3.7  
2 core: 3.8  
1 core: 3.8  
4 core: 3.5  
3 core: 3.6  
2 core: 3.7  
1 core: 3.7  
2 core: N/A  
1 core: 2.6  
SR12R  
SR0ZP  
SR12Q  
i7-3689Y  
i7-3689Y  
i5-3439Y  
L-1  
L-1  
L-1  
000306A9h  
000306A9h  
000306A9h  
1.5 /1600/ 350  
1.5 /1600/ 350  
1.5 /1600/ 350  
4
4
3
2,3,4,5,6  
2,3,4,5,6  
2,3,4,5,6  
2 core: N/A  
1 core: 2.6  
2 core: N/A  
1 core: 2.3  
Specification Update  
17  
Table 1.  
Processor Identification (Sheet 4 of 6)  
Core Frequency  
(GHz) /  
DDR3 (MHz) /  
Processor  
Graphics  
®
Max Intel  
Turbo Boost  
Technology  
2.0 Frequency  
Shared  
L3 Cache  
Size (MB)  
Processor  
Number  
Processor  
Signature  
Number  
Stepping  
Notes  
1
(GHz)  
Frequency  
2 core: N/A  
1 core: 2.3  
SR0ZN  
SR12S  
SR0ZQ  
SR12P  
SR0ZM  
SR12M  
SR13W  
SR0ZZ  
SR0VN  
SR0ZY  
SR103  
SR102  
SR105  
SR0VQ  
SR108  
SR109  
SR10A  
i5-3439Y  
i5-3339Y  
i5-3339Y  
i3-3229Y  
i3-3229Y  
2129Y  
L-1  
L-1  
L-1  
L-1  
L-1  
P-0  
P-0  
P-0  
P-0  
E-1  
P-0  
P-0  
P-0  
P-0  
P-0  
P-0  
P-0  
000306A9h  
000306A9h  
000306A9h  
000306A9h  
000306A9h  
000306A9h  
000306A9h  
000306A9h  
000306A9h  
000306A9h  
000306A9h  
000306A9h  
000306A9h  
000306A9h  
000306A9h  
000306A9h  
000306A9h  
1.5 /1600/ 350  
1.5 /1600/ 350  
1.5 /1600/ 350  
1.4 /1600/ 350  
1.4 /1600/ 350  
1.1 / 1600/ 350  
1.1 / 1600/ 350  
2.5/ 1600/ 650  
2.4/ 1600/ 650  
2.1/ 1600/ 650  
1.9/ 1600/ 650  
1.8/ 1600/ 650  
1.9/ 1600/ 350  
1.8/ 1600/ 350  
1.8/ 1600/ 350  
1.5/ 1600/ 350  
1.6/ 1600/ 350  
3
3
3
3
3
2
2
2
2
2
2
2
2
2
2
2
2
2,3,4,5,6  
2 core: N/A  
1 core: 2.2  
2,4,5,6  
2 core: N/A  
1 core: 2.2  
2,4,5,6  
2 core: N/A  
1 core: 1.4  
2,4  
2,4  
4
2 core: N/A  
1 core: 1.4  
2 core: N/A  
1 core: 1.1  
2 core: N/A  
1 core: 1.1  
1019Y  
4
2 core: N/A  
1 core: 2.5  
2030M  
2020M  
1020M  
1005M  
1000M  
2127U  
4
2 core: N/A  
1 core: 2.4  
4
2 core: N/A  
1 core: 2.1  
4
2 core: N/A  
1 core: 1.9  
4
2 core: N/A  
1 core: 1.8  
4
2 core: N/A  
1 core: 1.9  
4
2 core: N/A  
1 core: 1.8  
2117U  
4
2 core: N/A  
1 core: 1.8  
1037U  
4
2 core: N/A  
1 core: 1.5  
1007U  
4
2 core: N/A  
1 core: 1.6  
1017U  
4
3/4 Core: 3.1  
2 Core: 3.2  
1 Core: 3.3  
SR0NP  
SR0NC  
i7-3610QE  
i7-3615QE  
E-1  
E-1  
00306A9h  
00306A9h  
2.3 / 1600/ 650  
2.3 / 1600/ 650  
6
6
2,3,4,5,6,8  
2,3,4,5,6,8  
3/4 Core: 3.1  
2 Core: 3.2  
1 Core: 3.3  
18  
Specification Update  
Table 1.  
Processor Identification (Sheet 5 of 6)  
Core Frequency  
(GHz) /  
DDR3 (MHz) /  
Processor  
Graphics  
®
Max Intel  
Turbo Boost  
Technology  
2.0 Frequency  
Shared  
L3 Cache  
Size (MB)  
Processor  
Number  
Processor  
Signature  
Number  
Stepping  
Notes  
1
(GHz)  
Frequency  
3/4 Core: 2.8  
2 Core: 3.0  
1 Core: 3.1  
SR0ND  
SR0T5  
i7-3612QE  
i7-3555LE  
E-1  
L-1  
00306A9h  
00306A9h  
2.3 / 1600/ 650  
2.5 / 1600/ 550  
6
4
2,3,4,5,6,8  
2,3,4,5,6,8  
4 Core: 0  
3 Core: 0  
2 Core: 3.0  
1 Core: 3.2  
4 Core: 0  
3 Core: 0  
SR0T6  
SR0QJ  
SR0QK  
SR0WL  
SR0WM  
SR0WN  
SR10E  
SR10D  
i7-3517UE  
i5-3610ME  
i5-3610ME  
i3-3210ME  
i3-3120ME  
i3-3217UE  
1047UE  
L-1  
L-1  
L-1  
L-1  
L-1  
L-1  
P-0  
P-0  
00306A9h  
00306A9h  
00306A9h  
00306A9h  
00306A9h  
00306A9h  
00306A9h  
00306A9h  
1.7 / 1600/ 350  
2.7 / 1600/ 650  
2.7 / 1600/ 650  
2.4 / 1600/ 650  
2.4 / 1600/ 650  
1.6 / 1600/ 350  
1.4 / 1600/ 350  
2.2 / 1600/ 650  
4
3
3
3
3
3
2
2
2,3,4,5,6,8  
2,3,4,5,6,8  
2,3,4,5,6,8  
2,4,8  
2 Core: 2.6  
1 Core: 2.8  
4 Core: 0  
3 Core: 0  
2 Core: 3.2  
1 Core: 3.3  
4 Core: 0  
3 Core: 0  
2 Core: 3.2  
1 Core: 3.3  
4 Core: 0  
3 Core: 0  
2 Core: 0  
1 Core: 0  
4 Core: 0  
3 Core: 0  
2 Core: 0  
1 Core: 0  
2,4,8  
4 Core: 0  
3 Core: 0  
2 Core: 0  
1 Core: 0  
2,4,8  
4 Core: 0  
3 Core: 0  
2 Core: 0  
1 Core: 0  
4,8  
4 Core: 0  
3 Core: 0  
2 Core: 0  
1 Core: 0  
1020E  
4,8  
Specification Update  
19  
Table 1.  
Processor Identification (Sheet 6 of 6)  
Core Frequency  
(GHz) /  
DDR3 (MHz) /  
Processor  
Graphics  
®
Max Intel  
Turbo Boost  
Technology  
2.0 Frequency  
Shared  
L3 Cache  
Size (MB)  
Processor  
Number  
Processor  
Signature  
Number  
Stepping  
Notes  
1
(GHz)  
Frequency  
4 Core: 0  
3 Core: 0  
2 Core: 0  
1 Core: 0  
SR0VR  
SR10F  
1020E  
927UE  
P-0  
P-0  
00306A9h  
00306A9h  
2.2 / 1600/ 650  
2
1
4,8  
4,8  
4 Core: 0  
3 Core: 0  
2 Core: 0  
1 Core: 0  
1.5 / 1600/ 350  
Notes:  
®
1.  
This column indicates maximum Intel Turbo Boost Technology 2.0 frequency (GHz) for 4,3, 2 or 1  
cores active respectively.  
®
2.  
3.  
4.  
5.  
6.  
Intel Hyper-Threading Technology enabled.  
Intel Trusted Execution Technology (Intel TXT) enabled.  
Intel Virtualization Technology for IA-32, Intel 64 and Intel Architecture (Intel VT-x) enabled.  
Intel Virtualization Technology for Directed I/O (Intel VT-d) enabled.  
®
®
®
®
®
®
®
®
®
Intel AES-NI enabled.  
20  
Specification Update  
Errata  
BU1.  
The Processor May Report a #TS Instead of a #GP Fault  
Problem:  
A jump to a busy TSS (Task-State Segment) may cause a #TS (invalid TSS exception)  
instead of a #GP fault (general protection exception).  
Implication: Operation systems that access a busy TSS may get invalid TSS fault instead of a #GP  
fault. Intel has not observed this erratum with any commercially available software.  
Workaround: None identified.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU2.  
REP MOVS/STOS Executing with Fast Strings Enabled and Crossing  
Page Boundaries with Inconsistent Memory Types may use an  
Incorrect Data Size or Lead to Memory-Ordering Violations.  
Problem:  
Under certain conditions as described in the Software Developers Manual section “Out-  
of-Order Stores For String Operations in Pentium 4, Intel Xeon, and P6 Family  
Processors” the processor performs REP MOVS or REP STOS as fast strings. Due to this  
erratum fast string REP MOVS/REP STOS instructions that cross page boundaries from  
WB/WC memory types to UC/WP/WT memory types, may start using an incorrect data  
size or may observe memory ordering violations.  
Implication: Upon crossing the page boundary the following may occur, dependent on the new page  
memory type:  
• UC the data size of each write will now always be 8 bytes, as opposed to the  
original data size.  
• WP the data size of each write will now always be 8 bytes, as opposed to the  
original data size and there may be a memory ordering violation.  
• WT there may be a memory ordering violation.  
Workaround: Software should avoid crossing page boundaries from WB or WC memory type to UC,  
WP or WT memory type within a single REP MOVS or REP STOS instruction that will  
execute with fast strings enabled.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU3.  
IO_SMI Indication in SMRAM State Save Area May be Set Incorrectly  
Problem:  
The IO_SMI bit in SMRAM’s location 7FA4H is set to “1” by the CPU to indicate a System  
Management Interrupt (SMI) occurred as the result of executing an instruction that  
reads from an I/O port. Due to this erratum, the IO_SMI bit may be incorrectly set by:  
• A non-I/O instruction  
• SMI is pending while a lower priority event interrupts  
• A REP I/O read  
• A I/O read that redirects to MWAIT  
Implication: SMM handlers may get false IO_SMI indication.  
Workaround: The SMM handler has to evaluate the saved context to determine if the SMI was  
triggered by an instruction that read from an I/O port. The SMM handler must not  
restart an I/O instruction if the platform has not been configured to generate a  
synchronous SMI for the recorded I/O port address.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
Specification Update  
21  
 
BU4.  
Performance Monitor SSE Retired Instructions May Return Incorrect  
Values  
Problem:  
Performance Monitoring counter SIMD_INST_RETIRED (Event: C7H) is used to track  
retired SSE instructions. Due to this erratum, the processor may also count other types  
of instructions resulting in higher than expected values.  
Implication: Performance Monitoring counter SIMD_INST_RETIRED may report count higher than  
expected.  
Workaround: None identified.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU5.  
IRET under Certain Conditions May Cause an Unexpected Alignment  
Check Exception  
Problem:  
In IA-32e mode, it is possible to get an Alignment Check Exception (#AC) on the IRET  
instruction even though alignment checks were disabled at the start of the IRET. This  
can only occur if the IRET instruction is returning from CPL3 code to CPL3 code. IRETs  
from CPL0/1/2 are not affected. This erratum can occur if the EFLAGS value on the  
stack has the AC flag set, and the interrupt handler's stack is misaligned. In IA-32e  
mode, RSP is aligned to a 16-byte boundary before pushing the stack frame.  
Implication: In IA-32e mode, under the conditions given above, an IRET can get a #AC even if  
alignment checks are disabled at the start of the IRET. This erratum can only be  
observed with a software generated stack frame.  
Workaround: Software should not generate misaligned stack frames for use with IRET.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU6.  
Performance Monitoring Event FP_MMX_TRANS_TO_MMX May Not  
Count Some Transitions  
Problem:  
Performance Monitor Event FP_MMX_TRANS_TO_MMX (Event CCH, Umask 01H) counts  
transitions from x87 Floating Point (FP) to MMX™ instructions. Due to this erratum, if  
only a small number of MMX instructions (including EMMS) are executed immediately  
after the last FP instruction, a FP to MMX transition may not be counted.  
Implication: The count value for Performance Monitoring Event FP_MMX_TRANS_TO_MMX may be  
lower than expected. The degree of undercounting is dependent on the occurrences of  
teption). Intel has not observed this erratum with any commercially available software.  
Workaround: None identified  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU7.  
General Protection Fault (#GP) for Instructions Greater than 15 Bytes  
May be Preempted  
Problem:  
When the processor encounters an instruction that is greater than 15 bytes in length, a  
#GP is signaled when the instruction is decoded. Under some circumstances, the #GP  
fault may be preempted by another lower priority fault (e.g. Page Fault (#PF)).  
However, if the preempting lower priority faults are resolved by the operating system  
and the instruction retried, a #GP fault will occur.  
Implication: Software may observe a lower-priority fault occurring before or in lieu of a #GP fault.  
Instructions of greater than 15 bytes in length can only occur if redundant prefixes are  
placed before the instruction.  
Workaround: None identified.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
22  
Specification Update  
BU8.  
LBR, BTS, BTM May Report a Wrong Address when an Exception/  
Interrupt Occurs in 64-bit Mode  
Problem:  
An exception/interrupt event should be transparent to the LBR (Last Branch Record),  
BTS (Branch Trace Store) and BTM (Branch Trace Message) mechanisms. However,  
during a specific boundary condition where the exception/interrupt occurs right after  
the execution of an instruction at the lower canonical boundary (0x00007FFFFFFFFFFF)  
in 64-bit mode, the LBR return registers will save a wrong return address with bits 63  
to 48 incorrectly sign extended to all 1’s. Subsequent BTS and BTM operations which  
report the LBR will also be incorrect.  
Implication: LBR, BTS and BTM may report incorrect information in the event of an exception/  
interrupt.  
Workaround: None identified.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU9.  
Incorrect Address Computed For Last Byte of FXSAVE/FXRSTOR or  
XSAVE/XRSTOR Image Leads to Partial Memory Update  
Problem:  
A partial memory state save of the FXSAVE or XSAVE image or a partial memory state  
restore of the FXRSTOR or XRSTOR image may occur if a memory address exceeds the  
64KB limit while the processor is operating in 16-bit mode or if a memory address  
exceeds the 4GB limit while the processor is operating in 32-bit mode.  
Implication: FXSAVE/FXRSTOR or XSAVE/XRSTOR will incur a #GP fault due to the memory limit  
violation as expected but the memory state may be only partially saved or restored.  
Workaround: Software should avoid memory accesses that wrap around the respective 16-bit and  
32-bit mode memory limits.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU10.  
Values for LBR/BTS/BTM Will be Incorrect after an Exit from SMM  
Problem:  
After a return from SMM (System Management Mode), the CPU will incorrectly update  
the LBR (Last Branch Record) and the BTS (Branch Trace Store), hence rendering their  
data invalid. The corresponding data if sent out as a BTM on the system bus will also be  
incorrect. Note: This issue would only occur when one of the 3 above mentioned debug  
support facilities are used.  
Implication: The value of the LBR, BTS, and BTM immediately after an RSM operation should not be  
used.  
Workaround: None identified.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
Specification Update  
23  
BU11.  
EFLAGS Discrepancy on Page Faults and on EPT-Induced VM Exits  
after a Translation Change  
Problem:  
This erratum is regarding the case where paging structures are modified to change a  
linear address from writable to non-writable without software performing an  
appropriate TLB invalidation. When a subsequent access to that address by a specific  
instruction (ADD, AND, BTC, BTR, BTS, CMPXCHG, DEC, INC, NEG, NOT, OR, ROL/ROR,  
SAL/SAR/SHL/SHR, SHLD, SHRD, SUB, XOR, and XADD) causes a page fault or an EPT-  
induced VM exit, the value saved for EFLAGS may incorrectly contain the arithmetic flag  
values that the EFLAGS register would have held had the instruction completed without  
fault or VM exit. For page faults, this can occur even if the fault causes a VM exit or if  
its delivery causes a nested fault.  
Implication: None identified. Although the EFLAGS value saved by an affected event (a page fault or  
an EPT-induced VM exit) may contain incorrect arithmetic flag values, Intel has not  
identified software that is affected by this erratum. This erratum will have no further  
effects once the original instruction is restarted because the instruction will produce the  
same results as if it had initially completed without fault or VM exit.  
Workaround: If the handler of the affected events inspects the arithmetic portion of the saved  
EFLAGS value, then system software should perform a synchronized paging structure  
modification and TLB invalidation.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU12.  
B0-B3 Bits in DR6 For Non-Enabled Breakpoints May be Incorrectly Set  
Problem:  
Some of the B0-B3 bits (breakpoint conditions detect flags, bits [3:0]) in DR6 may be  
incorrectly set for non-enabled breakpoints when the following sequence happens:  
1. MOV or POP instruction to SS (Stack Segment) selector;  
2. Next instruction is FP (Floating Point) that gets FP assist  
3. Another instruction after the FP instruction completes successfully  
4. A breakpoint occurs due to either a data breakpoint on the preceding instruction or  
a code breakpoint on the next instruction.  
Due to this erratum a non-enabled breakpoint triggered on step 1 or step 2 may be  
reported in B0-B3 after the breakpoint occurs in step 4.  
Implication: Due to this erratum, B0-B3 bits in DR6 may be incorrectly set for non-enabled  
breakpoints.  
Workaround: Software should not execute a floating point instruction directly after a MOV SS or POP  
SS instruction.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
24  
Specification Update  
BU13.  
MCi_Status Overflow Bit May Be Incorrectly Set on a Single Instance  
of a DTLB Error  
Problem:  
A single Data Translation Look Aside Buffer (DTLB) error can incorrectly set the  
Overflow (bit [62]) in the MCi_Status register. A DTLB error is indicated by MCA error  
code (bits [15:0]) appearing as binary value, 000x 0000 0001 0100, in the MCi_Status  
register.  
Implication: Due to this erratum, the Overflow bit in the MCi_Status register may not be an accurate  
indication of multiple occurrences of DTLB errors. There is no other impact to normal  
processor functionality.  
Workaround: None identified.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU14.  
Debug Exception Flags DR6.B0-B3 Flags May be Incorrect for Disabled  
Breakpoints  
Problem:  
When a debug exception is signaled on a load that crosses cache lines with data  
forwarded from a store and whose corresponding breakpoint enable flags are disabled  
(DR7.G0-G3 and DR7.L0-L3), the DR6.B0-B3 flags may be incorrect.  
Implication: The debug exception DR6.B0-B3 flags may be incorrect for the load if the  
corresponding breakpoint enable flag in DR7 is disabled.  
Workaround: None identified.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU15.  
LER MSRs May Be Unreliable  
Problem:  
Due to certain internal processor events, updates to the LER (Last Exception Record)  
MSRs, MSR_LER_FROM_LIP (1DDH) and MSR_LER_TO_LIP (1DEH), may happen when  
no update was expected.  
Implication: The values of the LER MSRs may be unreliable.  
Workaround: None Identified.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU16.  
Storage of PEBS Record Delayed Following Execution of MOV SS or STI  
Problem:  
When a performance monitoring counter is configured for PEBS (Precise Event Based  
Sampling), overflow of the counter results in storage of a PEBS record in the PEBS  
buffer. The information in the PEBS record represents the state of the next instruction  
to be executed following the counter overflow. Due to this erratum, if the counter  
overflow occurs after execution of either MOV SS or STI, storage of the PEBS record is  
delayed by one instruction.  
Implication: When this erratum occurs, software may observe storage of the PEBS record being  
delayed by one instruction following execution of MOV SS or STI. The state information  
in the PEBS record will also reflect the one instruction delay.  
Workaround: None identified.  
Specification Update  
25  
BU17.  
PEBS Record not Updated when in Probe Mode  
Problem:  
When a performance monitoring counter is configured for PEBS (Precise Event Based  
Sampling), overflows of the counter can result in storage of a PEBS record in the PEBS  
buffer. Due to this erratum, if the overflow occurs during probe mode, it may be  
ignored and a new PEBS record may not be added to the PEBS buffer.  
Implication: Due to this erratum, the PEBS buffer may not be updated by overflows that occur  
during probe mode.  
Workaround: None identified.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU18.  
MONITOR or CLFLUSH on the Local XAPIC's Address Space Results in  
Hang  
Problem:  
If the target linear address range for a MONITOR or CLFLUSH is mapped to the local  
xAPIC's address space, the processor will hang.  
Implication: When this erratum occurs, the processor will hang. The local xAPIC's address space  
must be uncached. The MONITOR instruction only functions correctly if the specified  
linear address range is of the type write-back. CLFLUSH flushes data from the cache.  
Intel has not observed this erratum with any commercially available software.  
Workaround: Do not execute MONITOR or CLFLUSH instructions on the local xAPIC address space.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU19.  
Faulting MMX Instruction May Incorrectly Update x87 FPU Tag Word  
Problem:  
Under a specific set of conditions, MMX stores (MOVD, MOVQ, MOVNTQ, MASKMOVQ)  
which cause memory access faults (#GP, #SS, #PF, or #AC), may incorrectly update  
the x87 FPU tag word register.  
This erratum will occur when the following additional conditions are also met.  
• The MMX store instruction must be the first MMX instruction to operate on x87 FPU  
state (i.e. the x87 FP tag word is not already set to 0x0000).  
• For MOVD, MOVQ, MOVNTQ stores, the instruction must use an addressing mode  
that uses an index register (this condition does not apply to MASKMOVQ).  
Implication: If the erratum conditions are met, the x87 FPU tag word register may be incorrectly set  
to a 0x0000 value when it should not have been modified.  
Workaround: None identified.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU20.  
An Uncorrectable Error Logged in IA32_CR_MC2_STATUS May also  
Result in a System Hang  
Problem:  
Uncorrectable errors logged in IA32_CR_MC2_STATUS MSR (409H) may also result in a  
system hang causing an Internal Timer Error (MCACOD = 0x0400h) to be logged in  
another machine check bank (IA32_MCi_STATUS).  
Implication: Uncorrectable errors logged in IA32_CR_MC2_STATUS can further cause a system hang  
and an Internal Timer Error to be logged.  
Workaround: None identified.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
26  
Specification Update  
BU21.  
#GP on Segment Selector Descriptor that Straddles Canonical  
Boundary May Not Provide Correct Exception Error Code  
Problem:  
During a #GP (General Protection Exception), the processor pushes an error code on to  
the exception handler’s stack. If the segment selector descriptor straddles the  
canonical boundary, the error code pushed onto the stack may be incorrect.  
Implication: An incorrect error code may be pushed onto the stack. Intel has not observed this  
erratum with any commercially available software.  
Workaround: None identified.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU22.  
DR6.B0-B3 May Not Report All Breakpoints Matched When a MOV/POP  
SS is Followed by a Store or an MMX Instruction  
Problem:  
Normally, data breakpoints matches that occur on a MOV SS, r/m or POP SS will not  
cause a debug exception immediately after MOV/POP SS but will be delayed until the  
instruction boundary following the next instruction is reached. After the debug  
exception occurs, DR6.B0-B3 bits will contain information about data breakpoints  
matched during the MOV/POP SS as well as breakpoints detected by the following  
instruction. Due to this erratum, DR6.B0-B3 bits may not contain information about  
data breakpoints matched during the MOV/POP SS when the following instruction is  
either an MMX instruction that uses a memory addressing mode with an index or a  
store instruction.  
Implication: When this erratum occurs, DR6 may not contain information about all breakpoints  
matched. This erratum will not be observed under the recommended usage of the MOV  
SS,r/m or POP SS instructions (i.e., following them only with an instruction that writes  
(E/R)SP).  
Workaround: None identified.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU23.  
APIC Error “Received Illegal Vector” May be Lost  
Problem:  
APIC (Advanced Programmable Interrupt Controller) may not update the ESR (Error  
Status Register) flag Received Illegal Vector bit [6] properly when an illegal vector error  
is received on the same internal clock that the ESR is being written (as part of the  
write-read ESR access flow). The corresponding error interrupt will also not be  
generated for this case.  
Implication: Due to this erratum, an incoming illegal vector error may not be logged into ESR  
properly and may not generate an error interrupt.  
Workaround: None identified.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
Specification Update  
27  
BU24.  
Changing the Memory Type for an In-Use Page Translation May Lead  
to Memory-Ordering Violations  
Problem:  
Under complex microarchitectural conditions, if software changes the memory type for  
data being actively used and shared by multiple threads without the use of semaphores  
or barriers, software may see load operations execute out of order.  
Implication: Memory ordering may be violated. Intel has not observed this erratum with any  
commercially available software.  
Workaround: Software should ensure pages are not being actively used before requesting their  
memory type be changed.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU25.  
Reported Memory Type May Not Be Used to Access the VMCS and  
Referenced Data Structures  
Problem:  
Bits 53:50 of the IA32_VMX_BASIC MSR report the memory type that the processor  
uses to access the VMCS and data structures referenced by pointers in the VMCS. Due  
to this erratum, a VMX access to the VMCS or referenced data structures will instead  
use the memory type that the MTRRs (memory-type range registers) specify for the  
physical address of the access.  
Implication: Bits 53:50 of the IA32_VMX_BASIC MSR report that the WB (write-back) memory type  
will be used but the processor may use a different memory type.  
Workaround: Software should ensure that the VMCS and referenced data structures are located at  
physical addresses that are mapped to WB memory type by the MTRRs.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU26.  
LBR, BTM or BTS Records May have Incorrect Branch From  
Information After an EIST/T-state/S-state/C1E Transition or Adaptive  
Thermal Throttling  
Problem:  
The “From” address associated with the LBR (Last Branch Record), BTM (Branch Trace  
Message) or BTS (Branch Trace Store) may be incorrect for the first branch after a  
transition of:  
®
• EIST (Enhanced Intel SpeedStep Technology)  
• T-state (Thermal Monitor states)  
• S1-state (ACPI package sleep state)  
• C1E (Enhanced C1 Low Power state)  
• Adaptive Thermal Throttling  
Implication: When the LBRs, BTM or BTS are enabled, some records may have incorrect branch  
“From” addresses for the first branch after a transition of EIST, T-states, S-states, C1E,  
or Adaptive Thermal Throttling.  
Workaround: None identified.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
28  
Specification Update  
®
BU27.  
Fault Not Reported When Setting Reserved Bits of Intel VT-d Queued  
Invalidation Descriptors  
Problem:  
Reserved bits in the Queued Invalidation descriptors of Intel VT-d (Virtualization  
Technology for Directed I/O) are expected to be zero, meaning that software must  
program them as zero while the processor checks if they are not zero. Upon detection  
of a non-zero bit in a reserved field an Intel VT-d fault should be recorded. Due to this  
erratum the processor does not check reserved bit values for Queued Invalidation  
descriptors.  
Implication: Due to this erratum, faults will not be reported when writing to reserved bits of Intel  
VT-d Queued Invalidation Descriptors.  
Workaround: None identified.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU28.  
FP Data Operand Pointer May Be Incorrectly Calculated After an FP  
Access Which Wraps a 4-Gbyte Boundary in Code That Uses 32-Bit  
Address Size in 64-bit Mode  
Problem:  
The FP (Floating Point) Data Operand Pointer is the effective address of the operand  
associated with the last non-control FP instruction executed by the processor. If an 80-  
bit FP access (load or store) uses a 32-bit address size in 64-bit mode and the memory  
access wraps a 4-Gbyte boundary and the FP environment is subsequently saved, the  
value contained in the FP Data Operand Pointer may be incorrect.  
Implication: Due to this erratum, the FP Data Operand Pointer may be incorrect. Wrapping an 80-bit  
FP load around a 4-Gbyte boundary in this way is not a normal programming practice.  
Intel has not observed this erratum with any commercially available software.  
Workaround: If the FP Data Operand Pointer is used in a 64-bit operating system which may run code  
accessing 32-bit addresses, care must be taken to ensure that no 80-bit FP accesses  
are wrapped around a 4-Gbyte boundary.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU29.  
VMREAD/VMWRITE Instruction May Not Fail When Accessing an  
Unsupported Field in VMCS  
®
Problem:  
The Intel 64 and IA-32 Architectures Software Developer’s Manual, Volume 2B states  
that execution of VMREAD or VMWRITE should fail if the value of the instruction’s  
register source operand corresponds to an unsupported field in the VMCS (Virtual  
Machine Control Structure). The correct operation is that the logical processor will set  
the ZF (Zero Flag), write 0CH into the VM-instruction error field and for VMREAD leave  
the instruction’s destination operand unmodified. Due to this erratum, the instruction  
may instead clear the ZF, leave the VM-instruction error field unmodified and for  
VMREAD modify the contents of its destination operand.  
Implication: Accessing an unsupported field in VMCS will fail to properly report an error. In addition,  
VMREAD from an unsupported VMCS field may unexpectedly change its destination  
operand. Intel has not observed this erratum with any commercially available software.  
Workaround: Software should avoid accessing unsupported fields in a VMCS.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
Specification Update  
29  
®
BU30.  
Spurious Interrupts May be Generated From the Intel VT-d Remap  
Engine  
Problem:  
If software clears the F (Fault) bit 127 of the Fault Recording Register (FRCD_REG at  
offset 0x208 in Remap Engine BAR) by writing 1b through RW1C command (Read Write  
1 to Clear) when the F bit is already clear then a spurious interrupt from Intel VT-d  
(Virtualization Technology for Directed I/O) Remap Engine may be observed.  
Implication: Due to this erratum, spurious interrupts will occur from the Intel VT-d Remap Engine  
following RW1C clearing F bit.  
Workaround: None identified.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU31.  
Malformed PCIe Transactions May be Treated as Unsupported  
Requests Instead of as Critical Errors  
Problem:  
PCIe MSG/MSG_D TLPs (Transaction Layer Packets) with incorrect Routing Code as well  
as the deprecated TCfgRD and TCfgWr types should be treated as malformed  
transactions leading to a critical error. Due to this erratum, the integrated PCIe  
controller's root ports may treat such messages as UR (Unsupported Requests).  
Implication: Legacy malformed PCIe transactions may be treated as UR instead of as critical errors.  
Workaround: None identified.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU32.  
Reception of Certain Malformed Transactions May Cause PCIe Port to  
Hang Rather Than Reporting an Error  
Problem:  
If the processor receives an upstream malformed non posted packet for which the type  
field is IO, Configuration or the deprecated TCfgRd and the format is 4 DW header, then  
due to this erratum the integrated PCIe controller may hang instead of reporting the  
malformed packet error or issuing an unsupported request completion transaction.  
Implication: Due to this erratum, the processor may hang without reporting errors when receiving a  
malformed PCIe transaction. Intel has not observed this erratum with any commercially  
available device.  
Workaround: None identified. Upstream transaction initiators should avoid issuing unsupported  
requests with 4 DW header formats.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU33.  
Clock Modulation Duty Cycle Cannot be Programmed to 6.25%  
Problem:  
When programming field T_STATE_REQ of the IA32_CLOCK_MODULATION MSR (19AH)  
bits [3:0] to '0001, the actual clock modulation duty cycle will be 12.5% instead of the  
expected 6.25% ratio.  
Implication: Due to this erratum, it is not possible to program the clock modulation to a 6.25% duty  
cycle.  
Workaround: None identified.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
30  
Specification Update  
BU34.  
Processor May Fail to Acknowledge a TLP Request  
Problem:  
When a PCIe root port’s receiver is in Receiver L0s power state and the port initiates a  
Recovery event, it will issue Training Sets to the link partner. The link partner will  
respond by initiating an L0s exit sequence. Prior to transmitting its own Training Sets,  
the link partner may transmit a TLP (Transaction Layer Packet) request. Due to this  
erratum, the root port may not acknowledge the TLP request.  
Implication: After completing the Recovery event, the PCIe link partner will replay the TLP request.  
The link partner may set a Correctable Error status bit, which has no functional effect.  
Workaround: None identified.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU35.  
An Unexpected PMI May Occur After Writing a Large Value to  
IA32_FIXED_CTR2  
Problem:  
If the fixed-function performance counter IA32_FIXED_CTR2 MSR (30BH) is configured  
to generate a performance-monitor interrupt (PMI) on overflow and the counter’s value  
is greater than FFFFFFFFFFC0H, then this erratum may incorrectly cause a PMI if  
software performs a write to this counter.  
Implication: A PMI may be generated unexpectedly when programming IA32_FIXED_CTR2. Other  
than the PMI, the counter programming is not affected by this erratum as the  
attempted write operation does succeed.  
Workaround: None identified.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU36.  
A Write to the IA32_FIXED_CTR1 MSR May Result in Incorrect Value in  
Certain Conditions  
Problem:  
Under specific internal conditions, if software tries to write the IA32_FIXED_CTR1 MSR  
(30AH) a value that has all bits [31:1] set while the counter was just about to overflow  
when the write is attempted (i.e. its value was 0xFFFF FFFF FFFF), then due to this  
erratum the new value in the MSR may be corrupted.  
Implication: Due to this erratum, IA32_FIXED_CTR1 MSR may be written with a corrupted value.  
Workaround: Software may avoid this erratum by writing zeros to the IA32_FIXED_CTR1 MSR,  
before the desired write operation.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU37.  
PCIe* LTR Incorrectly Reported as Being Supported  
Problem:  
LTR (Latency Tolerance Reporting) is a new optional feature specified in PCIe rev. 2.1.  
The processor reports LTR as supported in LTRS bit in DCAP2 register (bus 0; Device 1;  
Function 0; offset 0xc4), but this feature is not supported.  
Implication: Due to this erratum, LTR is always reported as supported by the LTRS bit in the DCAP2  
register.  
Workaround: None identified.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
Specification Update  
31  
BU38.  
PerfMon Overflow Status Can Not be Cleared After Certain Conditions  
Have Occurred  
Problem:  
Under very specific timing conditions, if software tries to disable a PerfMon counter  
through MSR IA32_PERF_GLOBAL_CTRL (0x38F) or through the per-counter event-  
select (e.g. MSR 0x186) and the counter reached its overflow state very close to that  
time, then due to this erratum the overflow status indication in MSR  
IA32_PERF_GLOBAL_STAT (0x38E) may be left set with no way for software to clear it.  
Implication: Due to this erratum, software may be unable to clear the PerfMon counter overflow  
status indication.  
Workaround: Software may avoid this erratum by clearing the PerfMon counter value prior to  
disabling it and then clearing the overflow status indication bit.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU39.  
#GP May be Signaled When Invalid VEX Prefix Precedes Conditional  
Branch Instructions  
Problem:  
When a 2-byte opcode of a conditional branch (opcodes 0F8xH, for any value of x)  
instruction resides in 16-bit code-segment and is associated with invalid VEX prefix, it  
may sometimes signal a #GP fault (illegal instruction length > 15-bytes) instead of a  
#UD (illegal opcode) fault.  
Implication: Due to this erratum, #GP fault instead of a #UD may be signaled on an illegal  
instruction.  
Workaround: None identified.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU40.  
Interrupt From Local APIC Timer May Not Be Detectable While Being  
Delivered  
Problem:  
If the local-APIC timer’s CCR (current-count register) is 0, software should be able to  
determine whether a previously generated timer interrupt is being delivered by first  
reading the delivery-status bit in the LVT timer register and then reading the bit in the  
IRR (interrupt-request register) corresponding to the vector in the LVT timer register. If  
both values are read as 0, no timer interrupt should be in the process of being  
delivered. Due to this erratum, a timer interrupt may be delivered even if the CCR is 0  
and the LVT and IRR bits are read as 0. This can occur only if the DCR (Divide  
Configuration Register) is greater than or equal to 4. The erratum does not occur if  
software writes zero to the Initial Count Register before reading the LVT and IRR bits.  
Implication: Software that relies on reads of the LVT and IRR bits to determine whether a timer  
interrupt is being delivered may not operate properly.  
Workaround: Software that uses the local-APIC timer must be prepared to handle the timer  
interrupts, even those that would not be expected based on reading CCR and the LVT  
and IRR bits; alternatively, software can avoid the problem by writing zero to the Initial  
Count Register before reading the LVT and IRR bits.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
32  
Specification Update  
*
BU41.  
PCI Express Differential Peak-Peak Tx Voltage Swing May Violate the  
Specification  
Problem:  
Under certain conditions, including extreme voltage and temperature, the peak-peak  
voltage may be higher than the specification.  
®
Implication: Violation of PCI Express Base Specification of the VTX--DIFF-PP voltage. No failures  
have been observed due to this erratum.  
Workaround: None identified.  
BU42.  
PCMPESTRI, PCMPESTRM, VPCMPESTRI and VPCMPESTRM Always  
Operate with 32-bit Length Registers  
Problem:  
In 64-bit mode, using REX.W=1 with PCMPESTRI and PCMPESTRM or VEX.W=1 with  
VPCMPESTRI and VPCMPESTRM should support a 64-bit length operation with RAX/  
RDX. Due to this erratum, the length registers are incorrectly interpreted as 32-bit  
values.  
Implication: Due to this erratum, using REX.W=1 with PCMPESTRI and PCMPESTRM as well as  
VEX.W=1 with VPCMPESTRI and VPCMPESTRM do not result in promotion to 64-bit  
length registers.  
Workaround: It is possible for the BIOS to contain a workaround for this erratum.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU43.  
Multiple Performance Monitor Interrupts are Possible on Overflow of  
Fixed Counter 0  
Problem:  
The processor can be configured to issue a PMI (performance monitor interrupt) upon  
overflow of the IA32_FIXED_CTR0 MSR (309H). A single PMI should be observed on  
overflow of IA32_FIXED_CTR0, however multiple PMIs are observed when this erratum  
occurs.  
This erratum only occurs when IA32_FIXED_CTR0 overflows and the processor and  
counter are configured as follows:  
®
• Intel Hyper-Threading Technology is enabled  
• IA32_FIXED_CTR0 local and global controls are enabled  
• IA32_FIXED_CTR0 is set to count events only on its own thread  
(IA32_FIXED_CTR_CTRL MSR (38DH) bit [2] = ‘0).  
• PMIs are enabled on IA32_FIXED_CTR0 (IA32_FIXED_CTR_CTRL MSR bit [3] = ‘1)  
• Freeze_on_PMI feature is enabled (IA32_DEBUGCTL MSR (1D9H) bit [12] = ‘1)  
Implication: When this erratum occurs there may be multiple PMIs observed when  
IA32_FIXED_CTR0 overflows.  
Workaround: Disable the FREEZE_PERFMON_ON_PMI feature in IA32_DEBUGCTL MSR (1D9H)  
bit [12].  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
Specification Update  
33  
BU44.  
IA32_FEATURE_CONTROL MSR May be Uninitialized on a Cold Reset  
Problem:  
IA32_FEATURE_CONTROL MSR (3Ah) may have random values after RESET (including  
the reserved and Lock bits), and the read-modify-write of the reserved bits and/or the  
Lock bit being incorrectly set may cause an unexpected GP fault.  
Implication: Due to this erratum, an unexpected GP fault may occur and BIOS may not complete  
initialization.  
Workaround: It is possible for the BIOS to contain a workaround for this erratum.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU45.  
DR6.B0-B3 May Not Report All Breakpoints Matched When a MOV/POP  
SS is Followed by a REP MOVSB or STOSB  
Problem:  
Normally, data breakpoints matches that occur on a MOV SS, r/m or POP SS will not  
cause a debug exception immediately after MOV/POP SS but will be delayed until the  
instruction boundary following the next instruction is reached. After the debug  
exception occurs, DR6.B0-B3 bits will contain information about data breakpoints  
matched during the MOV/POP SS as well as breakpoints detected by the following  
instruction. Due to this erratum, DR6.B0-B3 bits may not contain information about  
data breakpoints matched during the MOV/POP SS when the following instruction is  
either an REP MOVSB or REP STOSB.  
Implication: When this erratum occurs, DR6 may not contain information about all breakpoints  
matched. This erratum will not be observed under the recommended usage of the MOV  
SS,r/m or POP SS instructions (i.e., following them only with an instruction that writes  
(E/R)SP).  
Workaround: None identified.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU46.  
Setting Hardware Autonomous Speed Disable Configuration Bit Will  
Block Initial Speed Upgrade  
Problem:  
The PCI Express* Base Specification Revision 3.0 states that the Hardware  
Autonomous Speed Disable bit (Link Control Register 2, bit 5) does not block the initial  
transition to the highest supported common link speed. Setting this bit will block all  
autonomous speed changes.  
Implication: Due to this erratum, if the Hardware Autonomous Speed Disable bit is set, a given PCIe  
link may remain at 2.5 GT/s transfer rate. This erratum has not been observed with any  
commercially available add-in cards.  
Workaround: It is possible for software to initiate a directed speed change.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU47.  
LTR Message is Not Treated as an Unsupported Request  
Problem:  
The PCIe* root port does not support LTR (Latency Tolerance Reporting) capability.  
However, a received LTR message is not treated as a UR (Unsupported Request).  
Implication: Due to this erratum, an LTR message does not generate a UR error.  
Workaround: None identified.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
34  
Specification Update  
BU48.  
64-bit REP MOVSB/STOSB May Clear The Upper 32-bits of RCX, RDI  
And RSI Before Any Data is Transferred  
Problem:  
If a REP MOVSB/STOSB is executed in 64-bit mode with an address size of 32 bits, and  
if an interrupt is being recognized at the start of the instruction operation, the upper  
32-bits of RCX, RDI and RSI may be cleared, even though no data has yet been copied  
or written.  
Implication: Due to this erratum, the upper 32-bits of RCX, RDI and RSI may be prematurely  
cleared.  
Workaround: It is possible for the BIOS to contain a workaround for this erratum.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU49.  
An Interrupt Recognized Prior to First Iteration of REP MOVSB/STOSB  
May Result EFLAGS.RF Being Incorrectly Set  
Problem:  
If a REP MOVSB/STOSB is executed and an interrupt is recognized prior to completion  
of the first iteration of the string operation, EFLAGS may be saved with RF=1 even  
though no data has been copied or stored. The Software Developer’s Manual states that  
RF will be set to 1 for such interrupt conditions only after the first iteration is complete.  
Implication: Software may not operate correctly if it relies on the value saved for EFLAGS.RF when  
an interrupt is recognized prior to the first iteration of a string instruction. Debug  
exceptions due to instruction breakpoints are delivered correctly despite this erratum;  
this is because the erratum occurs only after the processor has evaluated instruction-  
breakpoint conditions.  
Workaround: Software whose correctness depends on value saved for EFLAGS.RF by delivery of the  
affected interrupts can disable fast-string operation by clearing Fast-String Enable in bit  
0 in the IA32_MISC_ENABLE MSR (1A0H).  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU50.  
Accessing Physical Memory Space 0-640K through the Graphics  
Aperture May Cause Unpredictable System Behavior  
Problem:  
The physical memory space 0-640K when accessed through the graphics aperture may  
result in a failure for writes to complete or reads to return incorrect results.  
Implication: A hang or functional failure may occur during graphics operation such as OGL or OCL  
conformance tests, 2D/3D games and graphics intensive application.  
Workaround: It is possible for the BIOS to contain a workaround for this erratum.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU51.  
PEBS May Unexpectedly Signal a PMI After The PEBS Buffer is Full  
Problem:  
The Software Developer’s Manual states that no PMI should be generated when PEBS  
index reaches PEBS Absolute Maximum. Due to this erratum, a PMI may be generated  
even though the PEBS buffer is full.  
Implication: PEBS may trigger a PMI even though the PEBS index has reached the PEBS Absolute  
Maximum.  
Workaround: None identified.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
Specification Update  
35  
BU52.  
Instructions Retired Event May Over Count Execution of IRET  
Instructions  
Problem:  
Under certain conditions, the performance monitoring event Instructions Retired (Event  
C0H, Unmask 00H) may over count the execution of IRET instruction.  
Implication: Due to this erratum, performance monitoring event Instructions Retired may over  
count.  
Workaround: None identified.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU53.  
PCIe* Link May Unexpectedly Exit Loopback State  
Problem:  
The PCIe Port is capable of functioning as 3 independent PCIe controllers. Due to this  
erratum, if more than one of the controllers is in Loopback.Active state and configured  
as a loopback slave and if any one of these controllers transition to Loopback.Exit, all  
controllers in Loopback.Active will transition to Loopback.Exit.  
Implication: Loopback.Active state on a given Link may unexpectedly exit. Software should avoid  
configuring more than one of the PCIe Controllers as Loopback slave concurrently.  
Workaround: PCIe endpoints should avoid configuring more than one of PCIe Controllers as Loopback  
slave.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU54.  
The RDRAND Instruction Will Not Execute as Expected  
Problem:  
On processors that support the RDRAND instruction, that capability should be reported  
via the setting of CPUID.01H:ECX.RDRAND[bit 30]. Due to this erratum, that bit will  
not be set, and the execution of the RDRAND instruction will result in a #UD exception.  
Implication: Software will not be able to utilize the RDRAND instruction  
Workaround: It is possible for the BIOS to contain a workaround for this erratum to report RDRAND  
as present via CPUID and allow proper execution of RDRAND.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU55.  
A PCIe* Device That Initially Transmits Minimal Posted Data Credits  
May Cause a System Hang  
Problem:  
Under certain conditions, if a PCIe device that initially transmits posted data credits  
less than Max_Payload_Size/16 + 4 (16B/4DW is unit of data flow control) and is the  
target of a Peer-to-Peer write of Max_Payload_Size, the system may hang due to  
Posted Data credit starvation.  
Implication: Under certain conditions, the processor may encounter a Posted Data credit starvation  
scenario and hang.  
Workaround: A BIOS code change has been identified and may be implemented as a workaround for  
this erratum.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
36  
Specification Update  
BU56.  
PCI Express* Gen3 Receiver Return Loss May Exceed Specifications  
Problem:  
The PCIe Base Specification includes a graph that sets requirements for maximum  
receiver return loss versus frequency. Due to this erratum, the receiver return loss for  
common mode and differential mode may exceed those requirements at certain  
frequencies. Under laboratory conditions, Intel has observed violations of as much as  
1 dB.  
Implication: The PCI Express Gen3 Base Specification for receiver return loss may be exceeded. No  
functional failures have been observed due to this erratum.  
Workaround: None identified.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU57.  
Direct Access Via VT-d to The Processor Graphics Device May Lead to a  
System Hang  
Problem:  
Under a complex set of conditions, while using VT-d (Virtualization Technology for  
Directed I/O) with the processor graphics device, direct access to the virtualized  
processor graphics device can lead to a system hang or restart.  
Implication: Systems providing direct access to processor graphics device via VT-d may hang or  
restart. Intel has not observed this erratum with any commercially available system.  
Workaround: VMM’s should ensure that all processor graphics device interactions conform to  
®
guidance published in the Intel Open Source HD Graphics Programmer's Reference  
Manual and driver writers guide.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU58.  
An Event May Intervene Before a System Management Interrupt That  
Results from IN or INS  
Problem:  
If an I/O instruction (IN, INS, OUT, or OUTS) results in an SMI (system-management  
interrupt), the processor will set the IO_SMI bit at offset 7FA4H in SMRAM. This  
interrupt should be delivered immediately after execution of the I/O instruction so that  
the software handling the SMI can cause the I/O instruction to be re-executed. Due to  
this erratum, it is possible for another event (e.g., a nonmaskable interrupt) to be  
delivered before the SMI that follows the execution of an IN or INS instruction.  
Implication: If software handling an affected SMI uses I/O instruction restart, the handler for the  
intervening event will not be executed.  
Workaround: The SMM handler has to evaluate the saved context to determine if the SMI was  
triggered by an instruction that read from an I/O port. The SMM handler must not  
restart an I/O instruction if the platform has not been configured to generate a  
synchronous SMI for the recorded I/O port address.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
Specification Update  
37  
BU59.  
PCIe* May Associate Lanes That Are Not Part of Initial Link Training to  
L0 During Upconfiguration  
Problem:  
The processor should not associate any lanes that were not part of the initial link  
training in subsequent upconfiguration requests from an endpoint. Due to this erratum,  
the processor may associate any Lane that has exited Electrical Idle, even if it is  
beyond the width of the initial Link training.  
Implication: Upconfiguration requests may result in a Link wider than the initially-trained Link.  
Workaround: Endpoints must ensure that upconfiguration requests do not request a Link width wider  
than that negotiated during initial Link training.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU60.  
The Processor May Not Comply With PCIe* Equalization Preset  
Reflection Requirements for 8 GT/s Mode of Operation  
Problem:  
In endpoint-initiated transitions to Polling.Compliance at the 8 GT/s transfer rate, the  
processor must reflect, in its ordered sets, the Transmitter Preset requested by the  
endpoint regardless of preset legality. Due to this erratum, the processor will reflect the  
Transmitter Preset in use after an endpoint requests a reserved Transmitter Preset  
rather than the requested preset.  
Implication: Endpoints requiring reserved Transmitter Presets to be reflected may be adversely  
affected. Intel has not observed failures due to this erratum with any commercially  
available devices.  
Workaround: None identified.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU61.  
Processor May Issue PCIe* EIEOS at Incorrect Rate  
Problem:  
When initiating a Secondary Bus Reset or Link Disable procedure while a PCIe Link is in  
Recovery state, the processor should send an EIEOS (Electrical Idle Exit Ordered Set)  
after every 32 TS (Training Set) Ordered Sets. Due to this erratum, the processor may  
send an EIEOS after every 33 TS Ordered Sets.  
Implication: The processor may send an incorrect number of TS Ordered Sets between two EIEOS  
Ordered Sets when it initiates Secondary Bus Reset or Link Disable. Intel has not  
observed any failures with commercially available devices due to this erratum.  
Workaround: None identified.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU62.  
Reduced Swing Output Mode Needs Zero De-emphasis to be  
Supported in PCIe* 5GT/s Speed  
Problem:  
It may not be possible to support the PCIe Transmitter Preset 1 and/or Transmitter  
Preset 0 equalization requests in Phase 0 or Phase 2 of Recovery.Equalization LTSSM  
states when operating in 8GT/s in reduced or half swing mode, if 0dB transmitter de-  
emphasis needs to be supported when operating at 5GT/s.  
Implication: This erratum does not affect normal full swing mode of operation. Endpoints requiring  
0dB support in half-swing mode should avoid requesting Transmitter Preset 1 and/or  
Transmitter Preset 0 as preset requests in Phase 0 or Phase 2 of Recovery.Equalization  
when operating in 8GT/s.  
Workaround: None identified.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
38  
Specification Update  
BU63.  
PCIe* Root-port Initiated Compliance State Transmitter Equalization  
Settings May be Incorrect  
Problem:  
If the processor is directed to enter PCIe Polling.Compliance at 5.0 GT/s or 8.0 GT/s  
transfer rates, it should use the Link Control 2 Compliance Preset/De-emphasis field  
(bits [15:12]) to determine the correct de-emphasis level. Due to this erratum, when  
the processor is directed to enter Polling.Compliance from 2.5 GT/s transfer rate, it  
retains 2.5 GT/s de-emphasis values.  
Implication: The processor may operate in Polling.Compliance mode with an incorrect transmitter  
de-emphasis level.  
Workaround: None identified.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU64.  
PCIe* Controller May Incorrectly Log Errors on Transition to RxL0s  
Problem:  
Due to this erratum, if a link partner transitions to RxL0s state within 20 ns of entering  
L0 state, the PCIe controller may incorrectly log an error in ?Correctable Error  
Status.Receiver Error Status? field (Bus 0, Device 2, Function 0, 1, 2 and Device 6,  
Function 0, offset 1D0H, bit 0).  
Implication: Correctable receiver errors may be incorrectly logged. Intel has not observed any  
functional impact due to this erratum with any commercially available add-in cards.  
Workaround: None identified.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU65.  
Reception of Certain Malformed Transactions May Cause PCIe* Port to  
Hang Rather Than Reporting an Error  
Problem:  
If the processor receives an upstream malformed non posted packet for which the type  
field is IO, Configuration or the deprecated TCfgRd and the format is 4 DW header, then  
due to this erratum the integrated PCIe controller may hang instead of reporting the  
malformed packet error or issuing an unsupported request completion transaction.  
Implication: Due to this erratum, the processor may hang without reporting errors when receiving a  
malformed PCIe transaction. Intel has not observed this erratum with any commercially  
available device.  
Workaround: None identified. Upstream transaction initiators should avoid issuing unsupported  
requests with 4 DW header formats.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU66.  
PCIe* Link Width May Degrade After a Warm Reset  
Problem:  
PCIe link width may degrade after a warm reset if the Link is operating at 8.0 GT/s or  
5.0 GT/s transfer speeds prior to the reset.  
Implication: Due to this erratum, the PCIe link may retain to a narrower width, e.g. from x16 to x4.  
Workaround: A BIOS code change has been identified and may be implemented as a workaround for  
this erratum. .  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
Specification Update  
39  
BU67.  
MSR_PKG_Cx_RESIDENCY MSRs May Not be Accurate  
Problem:  
If the processor is in a package C-state for an extended period of time (greater  
than 40 seconds) with no wake events, the value in the  
MSR_PKG_C{2,3,6,7}_RESIDENCY MSRs (60DH and 3F8H–3FAH) will not be accurate.  
Implication: Utilities that report C-state residency times will report incorrect data in cases of long  
duration package C-states.  
Workaround: It is possible for the BIOS to contain a workaround for this erratum.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU68.  
Execution of Package C7 May Result in a Hang  
Problem:  
Under certain conditions, execution of Package C7 may result in a system hang on a  
subsequent C7 exit.  
Implication: Due to this erratum, the processor package may not exit Package C7, resulting in a  
system hang.  
Workaround: It is possible for the BIOS to contain a workaround for this erratum.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU69.  
PCIe* Link May Not Enter Loopback.Active When Directed  
Problem:  
When an endpoint directs the processor to enter loopback slave mode at 8 GT/s via TS1  
ordered sets with both the Loopback and Compliance Receive bits set, the PCIe link  
should directly enter Loopback.Active state. Due to this erratum, the processor must  
achieve block alignment on all looped back lanes prior to entering Loopback.Active.  
Implication: The processor will not enter Loopback.Active state as a loopback slave if any lane in a  
link cannot achieve block alignment.  
Workaround: None identified.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU70.  
Execution of VAESIMC or VAESKEYGENASSIST With An Illegal Value  
for VEX.vvvv May Produce a #NM Exception  
Problem:  
The VAESIMC and VAESKEYGENASSIST instructions should produce a #UD (Invalid-  
Opcode) exception if the value of the vvvv field in the VEX prefix is not 1111b. Due to  
this erratum, if CR0.TS is “1, the processor may instead produce a #NM (Device-Not-  
Available) exception.  
Implication: Due to this erratum, some undefined instruction encodings may produce a #NM instead  
of a #UD exception.  
Workaround: Software should always set the vvvv field of the VEX prefix to 1111b for instances of  
the VAESIMC and VAESKEYGENASSIST instructions.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU71.  
Unexpected #UD on VZEROALL/VZEROUPPER  
Problem:  
Execution of the VZEROALL or VZEROUPPER instructions in 64-bit mode with VEX.W set  
to 1 may erroneously cause a #UD (invalid-opcode exception).  
Implication: The affected instructions may produce unexpected invalid-opcode exceptions in 64-bit  
mode.  
Workaround: Compilers should encode VEX.W = 0 for the VZEROALL and VZEROUPPER instructions.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
40  
Specification Update  
BU72.  
PCIe* Root Port May Not Initiate Link Speed Change  
Problem:  
The PCIe Base specification requires the upstream component to maintain the PCIe link  
at the target link speed or the highest speed supported by both components on the  
link, whichever is lower. PCIe root port will not initiate the link speed change without  
being triggered by the software when the root port maximum link speed is configured  
to be 5.0 GT/s. System BIOS will trigger the link speed change under normal boot  
scenarios. However, BIOS is not involved in some scenarios such as link disable/re-  
enable or secondary bus reset and therefore the speed change may not occur unless  
initiated by the downstream component. This erratum does not affect the ability of the  
downstream component to initiate a link speed change. All known 5.0Gb/s-capable  
PCIe downstream components have been observed to initiate the link speed change  
without relying on the root port to do so.  
Implication: Due to this erratum, the PCIe root port may not initiate a link speed change during  
some hardware scenarios causing the PCIe link to operate at a lower than expected  
speed. Intel has not observed this erratum with any commercially available platform.  
Workaround: None identified.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU73.  
Successive Fixed Counter Overflows May be Discarded  
Problem:  
Under specific internal conditions, when using Freeze PerfMon on PMI feature (bit 12 in  
IA32_DEBUGCTL.Freeze_PerfMon_on_PMI, MSR 1D9H), if two or more PerfMon Fixed  
Counters overflow very closely to each other, the overflow may be mishandled for some  
of them. This means that the counter’s overflow status bit (in  
MSR_PERF_GLOBAL_STATUS, MSR 38EH) may not be updated properly; additionally,  
PMI interrupt may be missed if software programs a counter in Sampling-Mode (PMI bit  
is set on counter configuration).  
Implication: Successive Fixed Counter overflows may be discarded when Freeze PerfMon on PMI is  
used.  
Workaround: Software can avoid this by:  
1. Avoid using Freeze PerfMon on PMI bit  
2. Enable only one fixed counter at a time when using Freeze PerfMon on PMI  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU74.  
Execution of FXSAVE or FXRSTOR With the VEX Prefix May Produce a  
#NM Exception  
Problem:  
Attempt to use FXSAVE or FXRSTOR with a VEX prefix should produce a #UD (Invalid-  
Opcode) exception. If either the TS or EM flag bits in CR0 are set, a #NM (device-not-  
available) exception will be raised instead of #UD exception.  
Implication: Due to this erratum a #NM exception may be signaled instead of a #UD exception on  
an FXSAVE or an FXRSTOR with a VEX prefix.  
Workaround: Software should not use FXSAVE or FXRSTOR with the VEX prefix.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
Specification Update  
41  
BU75.  
VM Exits Due to “NMI-Window Exiting” May Not Occur Following a VM  
Entry to the Shutdown State  
Problem:  
If VM entry is made with the “virtual NMIs” and “NMI-window exiting, VM-execution  
controls set to 1, and if there is no virtual-NMI blocking after VM entry, a VM exit with  
exit reason “NMI window” should occur immediately after VM entry unless the VM entry  
put the logical processor in the wait-for SIPI state. Due to this erratum, such VM exits  
do not occur if the VM entry put the processor in the shutdown state.  
Implication: A VMM may fail to deliver a virtual NMI to a virtual machine in the shutdown state.  
Workaround: Before performing a VM entry to the shutdown state, software should check whether  
the “virtual NMIs” and “NMI-window exiting” VM-execution controls are both 1. If they  
are, software should clear “NMI-window exiting” and inject an NMI as part of VM entry.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU76.  
Execution of INVVPID Outside 64-Bit Mode Cannot Invalidate  
Translations For 64-Bit Linear Addresses  
Problem:  
Executions of the INVVPID instruction outside 64-bit mode with the INVVPID type  
“individual-address invalidation” ignore bits 63:32 of the linear address in the INVVPID  
descriptor and invalidate translations for bits 31:0 of the linear address.  
Implication: The INVVPID instruction may fail to invalidate translations for linear addresses that set  
bits in the range 63:32. Because this erratum applies only to executions outside 64-bit  
mode, it applies only to attempts by a 32-bit virtual-machine monitor (VMM) to  
invalidate translations for a 64-bit guest. Intel has not observed this erratum with any  
commercially available software.  
Workaround: None identified.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU77.  
PCIe* Controller May Not Properly Indicate Link Electrical Idle  
Condition  
Problem:  
The processor supports a x16 PCIe* port, which can be bifurcated into three  
independent links, enumerated as Bus 0, Device 1, Function 0-2. Due to this erratum, if  
the port is bifurcated and Function 1 or 2 is disabled, the PCIe controller may not  
properly indicate Link electrical idle condition to the Power Control Unit.  
Implication: An incorrect Link electrical idle indication may prevent the processor from entering the  
lowest power mode, which may cause higher power consumption on VccIO and VccSA.  
Intel has not observed any functional failure or performance impact due to this  
erratum.  
Workaround: If Bus 0, Device 1, Function 1 or 2 is disabled, do not configure the x16 port to allocate  
lanes to those functions.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
42  
Specification Update  
BU78.  
PCIe* Controller May Not Enter Loopback  
Problem:  
The PCIe controller is expected to enter loopback if any lane in the link receives two  
consecutive TS1 ordered sets with the Loopback bit set. Due to this erratum, if two  
consecutive TS1 ordered sets are received only on certain lanes, the controller may not  
enter loopback.  
Implication: Intel has not observed any functional issue with any commercially available PCIe  
devices.  
Workaround: None Identified  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU79.  
Link Margin Characterization May Hang Link  
Problem:  
The processor supports tools and mechanisms to characterize and measure margins for  
the PCIe interface. Due to this erratum, when performing link margin-to-failure  
characterization, it is possible that a high bit error rate may cause the link to hang.  
Implication: Under extreme conditions, poor link quality during link characterization may result in  
processor hang. Intel has not observed this erratum with any commercially available  
platforms under normal operating conditions.  
Workaround: None identified.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU80.  
Unused PCIe* Lanes May Report Correctable Errors  
Problem:  
Due to this erratum, during PCIe* link down configuration, unused lanes may report a  
Correctable Error Detected in Bus 0, Device 1, Function 0-2, and Device 6, Function 0,  
Offset 158H, Bit 0.  
Implication: Correctable Errors may be reported by a PCIe controller for unused lanes.  
Workaround: None identified.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU81.  
RDMSR of IA32_PERFEVTSEL{4-7} May Return Erroneous Information  
Problem:  
When CPUID.0AH:EAX[15:8] reports 8 general-purpose performance monitoring  
counters per logical processor, RDMSR of IA32_PERFEVTSEL{4-7} (MSR 18AH-18DH)  
may not return the same value previously written by software.  
Implication: Software should not rely on values read from these MSRs.  
Workaround: None identified.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
Specification Update  
43  
BU82.  
PCIe* Link May Fail Link Width Upconfiguration  
Problem:  
The processor supports PCIe Hardware Autonomous Width management, in which a  
PCIe link can autonomously vary its width. Due to this erratum, a link that performs a  
speed change while in a reduced width may no longer be able to return to a wider link  
width.  
Implication: PCIe links that perform speed changes while at a reduced link width may be limited to  
the link width in effect at the time of the speed change. Intel has not observed this  
erratum with any commercially available devices or platforms.  
Workaround: A BIOS code change has been identified and may be implemented as a workaround for  
this erratum.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU83.  
Graphics L3 Cache Parity Errors May Not be Detected  
Problem:  
The graphics engine should detect parity errors within the Graphics L3 cache. However,  
due to this erratum, graphics L3 cache parity errors may not be detected.  
Implication: There may be undetected parity errors from workloads submitted to the execution units  
of the graphics engine leading to unpredictable graphics system behavior.  
Workaround: It is possible for the graphics driver to contain a workaround for this erratum.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU84.  
A PCIe* Link That is in Link Disable State May Prevent DDR I/O  
Buffers From Entering a Power Gated State  
Problem:  
When entering Link Disable LTSSM state, the PCIe controller may not properly indicate  
the Link electrical idle condition.  
Implication: An incorrect Link electrical idle indication may prevent the DDR I/O buffers from  
entering a power gated state, which may cause higher power consumption on VccIO  
and VccSA. Intel has not observed any functional failure or performance impact due to  
this erratum.  
Workaround: A BIOS code change has been identified and may be implemented as a workaround for  
this erratum.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU85.  
Graphics L3 Cache Redundancy May Not Behave as Expected  
Problem:  
The processor graphics L3 cache is designed to have redundancy to improve resilience  
to cache related errors. Due to this erratum, that redundancy may not function as  
expected, resulting in a potential increase in L3 cache related errors.  
Implication: Under certain conditions, the lack of redundancy may lead to unpredictable graphics  
system behavior when processor graphics L3 cache is utilized.  
Workaround: It is possible for the BIOS to contain a workaround for this erratum.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
44  
Specification Update  
BU86.  
REP MOVSB May Incorrectly Update ECX, ESI, and EDI  
Problem:  
Under certain conditions, if the execution of a REP MOVSB instruction is interrupted,  
the values of ECX, ESI and EDI may contain values that represent a later point in the  
execution of the instruction than the actual interruption point.  
Implication: Due to this erratum ECX, ESI, and EDI may be incorrectly advanced, resulting in  
unpredictable system behavior.  
Workaround: It is possible for the BIOS to contain a workaround for this erratum.  
Status:  
For the steppings affected, see the Summary Tables of Changes  
BU87.  
Performance-Counter Overflow Indication May Cause Undesired  
Behavior  
Problem:  
Under certain conditions (listed below) when a performance counter overflows, its  
overflow indication may remain set indefinitely. This erratum affects the general-  
purpose performance counters IA32_PMC{0-7} and the fixed-function performance  
counters IA32_FIXED_CTR{0-2}. The erratum may occur if any of the following  
conditions are applied concurrent to when an actual counter overflow condition is  
reached:  
1. Software disables the counter either globally through the IA32_PERF_GLOBAL_CTRL  
MSR (38FH), or locally through the IA32_PERFEVTSEL{0-7} MSRs (186H-18DH), or the  
IA32_FIXED_CTR_CTRL MSR (38DH).  
2. Software sets the IA32_DEBUGCTL MSR (1D9H) FREEZE_PERFMON_ON_PMI bit  
[12].  
3. The processor attempts to disable the counters by updating the state of the  
IA32_PERF_GLOBAL_CTRL MSR (38FH) as part of transitions such as VM exit, VM entry,  
SMI, RSM, or processor C-state.  
Implication: Due to this erratum, the corresponding overflow status bit in  
IA32_PERF_GLOBAL_STATUS MSR (38DH) for an affected counter may not get cleared  
when expected. If a corresponding counter is configured to issue a PMI (performance  
monitor interrupt), multiple PMIs may be signaled from the same overflow condition.  
Likewise, if a corresponding counter is configured in PEBS mode (applies to only the  
general purpose counters), multiple PEBS events may be signaled.  
Workaround: None identified.  
Status:  
For the steppings affected, see the Summary Tables of Changes  
BU88.  
RDMSR of IA32_PERFEVTSEL4-7 May Return an Incorrect Result  
Problem:  
When CPUID.A.EAX[15:8] reports 8 general-purpose performance monitoring counters  
per logical processor, RDMSR of IA32_PERFEVTSEL4-7 (MSR 18AH:18DH) may not  
return the same value as previously written.  
Implication: Software should not rely on the value read from these MSRs. Writing these MSRs  
functions as expected.  
Workaround: None identified.  
Status:  
For the steppings affected, see the Summary Tables of Changes  
Specification Update  
45  
BU89.  
VEX.L is Not Ignored with VCVT*2SI Instructions  
Problem:  
The VEX.L bit should be ignored for the VCVTSS2SI, VCVTSD2SI, VCVTTSS2SI, and  
VCVTTSD2SI instructions, however due to this erratum the VEX.L bit is not ignored and  
will cause a #UD.  
Implication: Unexpected #UDs will be seen when the VEX.L bit is set to 1 with VCVTSS2SI,  
VCVTSD2SI, VCVTTSS2SI, and VCVTTSD2SI instructions.  
Workaround: Software should ensure that the VEX.L bit is set to 0 for all scalar instructions.  
Status:  
For the steppings affected, see the Summary Tables of Changes  
®
BU90.  
Intel Turbo Boost Technology May be Incorrectly Reported as  
®
Supported on Intel Core™ i3-3217U  
®
®
Problem:  
The Intel Core™ i3-3217U processor may incorrectly report support for Intel Turbo  
Boost Technology via CPUID.06H.EAX bit 1.  
Implication: The CPUID instruction may report Turbo Boost Technology as supported even though  
the processor does not permit operation above the Maximum Non-Turbo Frequency.  
Workaround: None identified  
Status:  
For the steppings affected, see the Summary Tables of Changes  
BU91.  
Concurrently Changing the Memory Type and Page Size May Lead to a  
System Hang  
Problem:  
Under a complex set of microarchitectural conditions, the system may hang if software  
changes the memory type and page size used to translate a linear address while a TLB  
(Translation Lookaside Buffer) holds a valid translation for that linear address.  
Implication: Due to this erratum, the system may hang. Intel has not observed this erratum with  
any commercially available software.  
Workaround: None identified. Please refer to Software Developer’s Manual, volume 3, section  
“Recommended Invalidation” for the proper procedure for concurrently changing page  
attributes and page size.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU92.  
MCI_ADDR May be Incorrect For Cache Parity Errors  
Problem:  
In cases when a WBINVD instruction evicts a line containing an address or data parity  
error (MCACOD of 0x124, and MSCOD of 0x10), the address of this error should be  
logged in the MCi_ADDR register. Due to this erratum, the logged address may be  
incorrect, even though MCi_Status.ADDRV (bit 63) is set.  
Implication: The address reported in MCi_ADDR may not be correct for cases of a parity error found  
during WBINVD execution.  
Workaround: None identified.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
46  
Specification Update  
BU93.  
During Package Power States Repeated PCIe* and/or DMI L1  
Transitions May Cause a System Hang  
Problem:  
Under a complex set of internal conditions and operating temperature, when the  
processor is in a deep power state (package C3, C6 or C7) and the PCIe and/or DMI  
links are toggling in and out of L1 state, the system may hang.  
Implication: Due to this erratum, the system may hang.  
Workaround: It is possible for the BIOS to contain a workaround for this erratum.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU94.  
Instruction Fetches Page-Table Walks May be Made Speculatively to  
Uncacheable Memory  
Problem:  
Page-table walks on behalf of instruction fetches may be made speculatively to  
uncacheable (UC) memory.  
Implication: If any paging structures are located at addresses in uncacheable memory that are used  
for memory-mapped I/O, such I/O operations may be invoked as a result of speculative  
execution that would never actually occur in the executed code path. Intel has not  
observed this erratum with any commercially available software.  
Workaround: Software should avoid locating paging structures at addresses in uncacheable memory  
that are used for memory-mapped I/O.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU95.  
The Processor May Not Properly Execute Code Modified Using A Floating-Point  
Store  
Problem:  
Under complex internal conditions, a floating-point store used to modify the next  
sequential instruction may result in the old instruction being executed instead of the  
new instruction.  
Implication: Self- or cross-modifying code may not execute as expected. Intel has not observed this  
erratum with any commercially available software.  
Workaround: None identified. Do not use floating-point stores to modify code.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU96.  
Execution of GETSEC[SEXIT] May Cause a Debug Exception to be Lost  
Problem:  
A debug exception occurring at the same time that GETSEC[SEXIT] is executed or when  
an SEXIT doorbell event is serviced may be lost.  
Implication: Due to this erratum, there may be a loss of a debug exception when it happens  
concurrently with the execution of GETSEC[SEXIT]. Intel has not observed this erratum  
with any commercially available software.  
Workaround: None identified.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
Specification Update  
47  
BU97.  
VM Exits Due to GETSEC May Save an Incorrect Value for “Blocking by STI” in the  
Context of Probe-Mode Redirection  
Problem:  
The GETSEC instruction causes a VM exit when executed in VMX non-root  
operation. Such a VM exit should set bit 0 in the Interruptability-state field in the  
virtual-machine control structure (VMCS) if the STI instruction was blocking interrupts  
at the time GETSEC commenced execution. Due to this erratum, a VM exit executed in  
VMX non-root operation may erroneously clear bit 0 if redirection to probe mode occurs  
on the GETSEC instruction.  
Implication: After returning from probe mode, a virtual interrupt may be incorrectly delivered prior  
to GETSEC instruction. Intel has not observed this erratum with any commercially  
software.  
Workaround: None identified.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU98.  
®
Problem:  
Specific source-copy blitter instructions in Intel HD Graphics 2500 and 4000 Processor  
may result in unpredictable behavior when a blit source and destination overlap.  
Implication: Due to this erratum, the processor may exhibit unpredictable graphics controller  
behavior. Intel has not observed this erratum with any commercially available software.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU99.  
IA32_MC5_CTL2 is Not Cleared by a Warm Reset  
Problem:  
IA32_MC5_CTL2 MSR (285H) is documented to be cleared on any reset. Due to this  
erratum this MSR is only cleared upon a cold reset.  
Implication: The algorithm documented in Software Developer's Manual, Volume 3, section titled  
"CMCI Initialization” or any other algorithm that counts the IA32_MC5_CTL2 MSR being  
cleared on reset will not function as expected after a warm reset.  
Workaround: None identified.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU100.  
CPUID Instruction May Not Report the Processor Number in the Brand  
®
String for Intel Core™ i3-3227U and i5-3337U Processors.  
Problem:  
When the CPUID instruction is executed with EAX = 80000002H, 80000003H, and  
80000004H, the returned brand string may be incomplete; it may be missing the  
processor number.  
Implication: When this erratum occurs, the processor may be missing the processor number in the  
®
brand string. In addition, if the affected processors are paired with the Intel 7 Series  
Chipset BD82UM77 chipset, the BIOS may incorrectly report this combination as  
unsupported.  
Workaround: It is possible for the BIOS to contain a workaround for this erratum, except if paired  
with the Intel 7 Series Chipset BD82UM77 chipset.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU101.  
Performance Monitor Counters May Produce Incorrect Results  
Problem:  
When operating with SMT enabled, a memory at-retirement performance monitoring  
event (from the list below) may be dropped or may increment an enabled event on the  
48  
Specification Update  
corresponding counter with the same number on the physical core’s other thread rather  
than the thread experiencing the event. Processors with SMT disabled in BIOS are not  
affected by this erratum.  
The list of affected memory at-retirement events is as follows:  
MEM_UOP_RETIRED.LOADS  
MEM_UOP_RETIRED.STORES  
MEM_UOP_RETIRED.LOCK  
MEM_UOP_RETIRED.SPLIT  
MEM_UOP_RETIRED.STLB_MISS  
MEM_LOAD_UOPS_RETIRED.HIT_LFB  
MEM_LOAD_UOPS_RETIRED.L1_HIT  
MEM_LOAD_UOPS_RETIRED.L2_HIT  
MEM_LOAD_UOPS_RETIRED.LLC_HIT  
MEM_LOAD_UOPS_MISC_RETIRED.LLC_MISS  
MEM_LOAD_UOPS_LLC_HIT_RETIRED.XSNP_HIT  
MEM_LOAD_UOPS_LLC_HIT_RETIRED.XSNP_HITM  
MEM_LOAD_UOPS_LLC_HIT_RETIRED.XSNP_MISS  
MEM_LOAD_UOPS_LLC_HIT_RETIRED.XSNP_NONE  
MEM_LOAD_UOPS_RETIRED.LLC_MISS  
MEM_LOAD_UOPS_LLC_MISS_RETIRED.LOCAL_DRAM  
MEM_LOAD_UOPS_LLC_MISS_RETIRED.REMOTE_DRAM  
MEM_LOAD_UOPS_RETIRED.L2_MISS  
Implication: Due to this erratum, certain performance monitoring event may produce unreliable  
results when SMT is enabled.  
Workaround: None identified.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU102.  
The Corrected Error Count Overflow Bit in IA32_ MC0_STATUS is Not  
Updated After a UC Error is Logged  
Problem:  
When a UC (uncorrected) error is logged in the IA32_MC0_STATUS MSR (401H),  
corrected errors will continue to update the lower 14 bits (bits 51:38) of the Corrected  
Error Count. Due to this erratum, the sticky count overflow bit (bit 52) of the Corrected  
Error Count will not get updated after a UC error is logged.  
Implication: The Corrected Error Count Overflow indication will be lost if the overflow occurs after an  
uncorrectable error has been logged.  
Workaround: None identified.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU103.  
Spurious VT-d Interrupts May Occur When the PFO Bit is Set  
Problem:  
When the PFO (Primary Fault Overflow) field (bit [0] in the VT-d FSTS [Fault Status]  
register) is set to 1, further faults should not generate an interrupt. Due to this  
erratum, further interrupts may still occur.  
Implication: Unexpected Invalidation Queue Error interrupts may occur. Intel has not observed this  
erratum with any commercially available software.  
Workaround: Software should be written to handle spurious VT-d fault interrupts.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
Specification Update  
49  
BU104.  
Processor May Livelock During On Demand Clock Modulation  
Problem:  
The processor may livelock when (1) a processor thread has enabled on demand clock  
modulation via bit 4 of the IA32_CLOCK_MODULATION MSR (19AH) and the clock  
modulation duty cycle is set to 12.5% (02H in bits 3:0 of the same MSR), and (2) the  
other processor thread does not have on demand clock modulation enabled and that  
thread is executing a stream of instructions with the lock prefix that either split a  
cacheline or access UC memory.  
Implication: Program execution may stall on both threads of the core subject to this erratum.  
Workaround: This erratum will not occur if clock modulation is enabled on all threads when using on  
demand clock modulation or if the duty cycle programmed in the  
IA32_CLOCK_MODULATION MSR is 18.75% or higher.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU105.  
IA32_VMX_VMCS_ENUM MSR (48AH) Does Not Properly Report The Highest Index  
Value Used For VMCS Encoding  
Problem:  
IA32_VMX_VMCS_ENUM MSR (48AH) bits 9:1 report the highest index value used for  
any VMCS encoding. Due to this erratum, the value 21 is returned in bits 9:1 although  
there is a VMCS field whose encoding uses the index value 23.  
Implication: Software that uses the value reported in IA32_VMX_VMCS_ENUM[9:1] to read and write  
all VMCS fields may omit one field.  
Workaround:  
None identified.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU106.  
The Upper 32 Bits of CR3 May be Incorrectly Used With 32-Bit Paging  
Problem:  
When 32-bit paging is in use, the processor should use a page directory located at the 32-  
bit physical address specified in bits 31:12 of CR3; the upper 32 bits of CR3 should be  
ignored. Due to this erratum, the processor will use a page directory located at the 64-bit  
physical address specified in bits 63:12 of CR3.  
Implication: The processor may use an unexpected page directory or, if EPT (Extended Page Tables)  
is in use, cause an unexpected EPT violation. This erratum applies only if software enters  
64-bit mode, loads CR3 with a 64-bit value, and then returns to 32-bit paging without  
changing CR3. Intel has not observed this erratum with any commercially available  
software.  
Workaround: Software that has executed in 64-bit mode should reload CR3 with a 32-bit value before  
returning to 32-bit paging.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU107.  
EPT Violations May Report Bits 11:0 of Guest Linear Address  
Incorrectly  
Problem:  
If a memory access to a linear address requires the processor to update an accessed or  
dirty flag in a paging-structure entry and if that update causes an EPT violation, the  
processor should store the linear address into the “guest linear address” field in the  
VMCS. Due to this erratum, the processor may store an incorrect value into bits 11:0 of  
50  
Specification Update  
this field. (The processor correctly stores the guest-physical address of the paging-  
structure entry into the “guest-physical address” field in the VMCS.)  
Implication: Software may not be easily able to determine the page offset of the original memory  
access that caused the EPT violation. Intel has not observed this erratum to impact the  
operation of any commercially available software.  
Workaround: Software requiring the page offset of the original memory access address can derive it by  
simulating the effective address computation of the instruction that caused the EPT  
violation.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU108.  
IA32_VMX_VMCS_ENUM MSR (48AH) Does Not Properly Report The  
Highest Index Value Used For VMCS Encoding  
Problem:  
IA32_VMX_VMCS_ENUM MSR (48AH) bits 9:1 report the highest index value used for  
any VMCS encoding. Due to this erratum, the value 21 is returned in bits 9:1 although  
there is a VMCS field whose encoding uses the index value 23.  
Implication: Software that uses the value reported in IA32_VMX_VMCS_ENUM[9:1] to read and  
write all VMCS fields may omit one field.  
Workaround:  
None identified.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU109.  
DMA Remapping Faults for the Graphics VT-d Unit May Not Properly  
Report Type of Faulted Request  
Problem:  
When a fault occurs during DMA remapping of Graphics accesses at the Graphics VT-d  
unit, the type of faulted request (read or write) should be reported in bit 126 of the  
FRCD_REG register in the remapping hardware memory map register set. Due to this  
erratum, the request type may not be reported correctly.  
Implication: Software processing the DMA remapping faults may not be able to determine the type  
of faulting graphics device DMA request.  
Workaround:  
None identified.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
®
BU110.  
Intel Trusted Execution Technology ACM Authentication Failure  
Problem:  
SINIT ACM 3rd_gen_i5_i7-SINIT_51.BIN or earlier are revoked and will not launch with  
new processor configuration information.  
Implication: Due to this erratum, SINIT ACM 3rd_gen_i5_i7-SINIT_51.BIN or earlier will fail to run.  
®
Workaround: It is possible for the BIOS to contain a workaround for this erratum. All Intel TXT enabled  
software must use SINIT ACM 3rd_gen_i5_i7-SINIT_67.BIN or later.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
BU111.  
Virtual-APIC Page Accesses With 32-Bit PAE Paging May Cause a  
System Crash  
Problem:  
If a logical processor has EPT (Extended Page Tables) enabled, is using 32-bit PAE  
paging, and accesses the virtual-APIC page then a complex sequence of internal  
Specification Update  
51  
processor micro-architectural events may cause an incorrect address translation or  
machine check on either logical processor.  
Implication: This erratum may result in unexpected faults, an uncorrectable TLB error logged in  
IA32_MCi_STATUS.MCACOD (bits [15:0]) with a value of 0000_0000_0001_xxxxb  
(where x stands for 0 or 1), a guest or hyper visor crash, or other unpredictable system  
behavior.  
Workaround: It is possible for the BIOS to contain a workaround for this erratum.  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
®
BU112.  
Address Translation Faults for Intel VT-d May Not be Reported for  
Display Engine Memory Accesses  
®
®
Problem:  
The Intel VT-d (Intel Virtualization Technology for Directed I/O) hardware unit  
supporting the Processor Graphics device (Bus 0; Device 2; Function 0) may not report  
address translation faults detected on Display Engine memory accesses when the  
Context Cache is disabled or during time periods when Context Cache is being  
invalidated.  
Implication: Due to this erratum, Display Engine accesses that fault are correctly aborted but may not  
be reported in the FSTS_REG fault reporting register (GFXVTDBAR offset 034H).  
Workaround: None identified  
Status:  
For the steppings affected, see the Summary Tables of Changes.  
§ §  
52  
Specification Update  
Specification Changes  
The Specification Changes listed in this section apply to the following documents:  
®
• Intel 64 and IA-32 Architectures Software Developer’s Manual, Volume 1: Basic  
Architecture  
®
• Intel 64 and IA-32 Architectures Software Developer’s Manual, Volume 2A:  
Instruction Set Reference Manual A-M  
®
• Intel 64 and IA-32 Architectures Software Developer’s Manual, Volume 2B:  
Instruction Set Reference Manual N-Z  
®
• Intel 64 and IA-32 Architectures Software Developer’s Manual, Volume 3A:  
System Programming Guide  
®
• Intel 64 and IA-32 Architectures Software Developer’s Manual, Volume 3B:  
System Programming Guide  
There are no new Specification Changes in this Specification Update revision.  
§ §  
Specification Update  
53  
 
Specification Clarifications  
The Specification Clarifications listed in this section may apply to the following  
documents:  
®
• Intel 64 and IA-32 Architectures Software Developer’s Manual, Volume 1: Basic  
Architecture  
®
• Intel 64 and IA-32 Architectures Software Developer’s Manual, Volume 2A:  
Instruction Set Reference Manual A-M  
®
• Intel 64 and IA-32 Architectures Software Developer’s Manual, Volume 2B:  
Instruction Set Reference Manual N-Z  
®
• Intel 64 and IA-32 Architectures Software Developer’s Manual, Volume 3A:  
System Programming Guide  
®
• Intel 64 and IA-32 Architectures Software Developer’s Manual, Volume 3B:  
System Programming Guide  
There are no new Specification Changes in this Specification Update revision.  
§ §  
54  
Specification Update  
 
Documentation Changes  
The Documentation Changes listed in this section apply to the following documents:  
®
• Intel 64 and IA-32 Architectures Software Developer’s Manual, Volume 1: Basic  
Architecture  
®
• Intel 64 and IA-32 Architectures Software Developer’s Manual, Volume 2A:  
Instruction Set Reference Manual A-M  
®
• Intel 64 and IA-32 Architectures Software Developer’s Manual, Volume 2B:  
Instruction Set Reference Manual N-Z  
®
• Intel 64 and IA-32 Architectures Software Developer’s Manual, Volume 3A:  
System Programming Guide  
®
• Intel 64 and IA-32 Architectures Software Developer’s Manual, Volume 3B:  
System Programming Guide  
All Documentation Changes will be incorporated into a future version of the appropriate  
Processor documentation.  
®
Note:  
Documentation changes for Intel 64 and IA-32 Architecture Software Developer's  
®
Manual volumes 1, 2A, 2B, 3A, and 3B will be posted in a separate document, Intel 64  
and IA-32 Architecture Software Developer's Manual Documentation Changes. Follow  
the link below to become familiar with this file.  
There are no new Documentation Changes in this Specification Update revision.  
On-Demand Clock Modulation Feature Clarification  
BU1.  
®
Software Controlled Clock Modulation section of the Intel 64 and IA-32 Architectures  
Software Developer's Manual, Volume 3B: System Programming Guide will be modified  
to differentiate On-demand clock modulation feature on different processors. The  
clarification will state:  
For Hyper-Threading Technology enabled processors, the IA32_CLOCK_MODULATION  
register is duplicated for each logical processor. In order for the On-demand clock  
modulation feature to work properly, the feature must be enabled on all the logical  
processors within a physical processor. If the programmed duty cycle is not identical for  
all the logical processors, the processor clock will modulate to the highest duty cycle  
programmed for processors if the CPUID DisplayFamily_DisplayModel signatures is  
listed in Table 14-2. For all other processors, if the programmed duty cycle is not  
identical for all logical processors in the same core, the processor will modulate at the  
lowest programmed duty cycle.  
For multiple processor cores in a physical package, each core can modulate to a  
programmed duty cycle independently.  
For the P6 family processors, on-demand clock modulation was implemented through  
the chipset, which controlled clock modulation through the processor’s STPCLK# pin.  
Table 14-2. CPUID Signatures for Legacy Processors That Resolve to Higher  
Performance Setting of Conflicting Duty Cycle Requests  
Specification Update  
55  
 
DisplayFamily_Displa  
yModel  
DisplayFamily_Display  
Model  
DisplayFamily_Displa  
yModel  
DisplayFamily_Display  
Model  
0F_xx  
06_1F  
06_2C  
06_36  
06_1C  
06_25  
06_2E  
06_1A  
06_26  
06_2F  
06_1E  
06_27  
06_35  
§ §  
56  
Specification Update  

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