MK3001GRRB 2.5-inch Hard Disk Drive for Enterprise Use
with 300 Gbyte Capacity and 15,000 rpm Rotational Speed
By Toru IWAMOTO / Akihiko MAKITA / Tatsuro SASAMOTO / Keiichi YORIMITSU
Hard disk drives (HDDs) for enterprise use are primary storage devices installed in mission-critical information systems
such as servers and storage systems. In this field, HDDs must be able to provide high reliability for long-term continuous
workloads (24 hours a day, seven days a week), as well as high performance including a high data transfer rate and high-speed
access. Low power consumption has also become essential in recent years.
In response to the needs of the market, Toshiba has developed the MK3001GRRB 2.5-inch HDD for enterprise use with a
capacity of 300 Gbyte and a rotational speed of 15,000 rpm. The MK3001GRRB achieves a high data transfer rate of 200
Mbit/s, a fast average seek time of 2.7 ms, and low power consumption of 4.0 W in idle state.
1. Introduction
Table 1 Main specifications of MK3001GRRB 2.5-inch HDD for enterprise use
Specifications
As cloud computing becomes increasingly popular,
Item
MK3001GRRB
MK1401GRRB
transaction processing that is faster than ever before is
being demanded of servers and storage systems to store
and manage various types of information. As the main
storage device in mission-critical information processing
systems, enterprise-class HDDs are required to have high
performance (e.g., high data transfer rates and high-speed
access) in addition to high reliability (to realize continuous
operation for extended periods of time).
Interface
SAS 2.0
6
Interface speed (Gbit/s)
Storage capacity
(Gbit/s)
(GB)
300
2
147
1
Disks
(QTY)
(QTY)
4
2
Heads
(Embedded HDI sensor) (Embedded HDI sensor)
Idle mode
4.0
3.0
3.8
2.8
Power consumption (W)
Low-RPM idle mode
Rotation speed (rpm)
15,000
147–200
2.7
Sustained data trans. rate
(MB/s)
(1) High reliability
Avg. seek time (during read)
MTBF
(106 h)
MTBF: Mean Time between Failures
(ms)
High reliability is required to ensure continuous
operation (24 hours a day, 7 days a week) for five
years.
1.6
HDI: Head Disk Interface
(2) High performance
enabling up to 200 MB/s sustained data transfer rates.
Also, it enables high-speed data access with an average
seek time of 2.7 ms. Further, it achieves low power
consumption, consuming only 4.0 W while in idle mode.
For the interface, we employed SAS 2.0 (Serial Attached
SCSI [Small Computer System Interface] 2.0), which is the
mainstream HDD interface for enterprise use.
High data transfer rates and high-speed access are
essential for processing large amounts of data within
a short period of time.
In addition, the recent promotion of energy conservation
and green products has led to requirements for low-power
consumption storage device.
In response to these requests, Toshiba developed the
MK3001GRRB 2.5-inch HDD. This product achieves
high performance and high reliability with 15,000 rpm
rotational speed, while delivering low power consumption.
In addition to the MK3001GRRB (storage capacity: 300
GB), we have the MK1401GRRB (storage capacity: 147 GB)
and encrypting models such as the MK3001GRRR and the
MK1401GRRR in the lineup. The basic specifications are
listed in Table 1.
2. Drive Overview
Table 1 shows the brief specifications of the
MK3001GRRB 2.5-inch HDD. The drive has a rotation
speed of 15,000 rpm and a storage capacity of 300 GB;
In the following sections, we describe the hardware and
firmware technologies that we developed to enable both
high reliability and high performance.
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1 ms
VCM current
Head position
Seek status
End of seek movement
During seek
Figure 3 Example of finite element method (FEM) analysis—By conducting large-
scale FEM analysis of the entirety of the HDD’s mechanical components, the shapes and
structures of each component were optimized, enabling high actuator performance.
Figure 4 Seek waveform—Alternate seek waveforms with 1/3 of the full stroke
distances; maximum acceleration exceeding 200 G during seek operations.
4. Firmware Technologies
The drive’s firmware consists of the following two function
structures.
100
With RV-FF
80
(1) Servo control functions
Controls the FDB motor, the VCM for head positioning
and seeking, etc.
60
40
20
0
Without RV-FF
(2) Controller firmware functions
Controls the interface that handles commands from
the host as well as the interfaces with the servo con-
trol and cache control functions.
0
20
40
60
80
100
Angular Acceleration of the HDD Case (rad/s2)
4.1. Servo control functions
Figure 5 Comparison of Performance with/without RV-FF Servo—Without RV-
FF, the performance degradation can be observed at 20 rad/s2 or more; with RV-FF, no
performance degradation can be observed under 100 rad/s2. Anti-vibration performance
is greatly improved.
The drive achieves an average seek time of 2.7 ms. The
drive accelerates and decelerates the carriage with a
maximum acceleration exceeding 200 G; its maximum
speed reaches 3 m/s. After such rapid acceleration and
deceleration movements, the drive must quickly and stably
follow the target track. Although the width of one track is
only approximately 90 nm, the heads must be positioned
exactly above the center of the tracks. For this reason, we
had to significantly improve the servo feedback control
loop gain. We also optimized the current waveforms
during seeking by taking into consideration the resonance
frequency of the actuator in order to reduce residual
vibrations and carriage acoustic noise (Figure 4).
also expanded the RV-FF frequency band. These two
improvements contributed to a significant improvement for
the external vibration stress (Figure 5).
We can also reduce power consumption by powering
down circuits individually and reducing the rotation speed
of the disks that are not carrying out read/write operations
after the drive carries out seek movements or while it is in
an idle state. We also optimized the FDB spin-up control,
head loading and unloading controls, and reduced acoustic
noise.
As part of our efforts to realize the above, we also
increased the sampling frequency of the servo controller,
used faster processors, and optimized servo controller
loop shapes.
By adopting such technologies, we enabled high
performance, low power consumption, and low acoustic
noise.
Enterprise class HDDs use require consideration of not
only the vibrations inside HDDs but also the influence
of external vibrations. In servers and storage systems,
multiple built-in HDDs as well as the cooling fans
may cause vibrations. To suppress the performance
degradation caused by such vibrations, we used rotational
vibration feed forward (RV-FF) technology to improve
the above-mentioned actuator feedback control. We
4.2. Controller firmware functions
This drive is compatible with the SAS 2.0 industry
standard and enables an interface speed of up to 6
Gbits/s.
The following sections describe the drive’s maintainability
and high reliability as well as its high functionality, high
performance, and low power consumption.
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(2) Data queuing function
4.2.1. Maintainability and high reliability
Reduces processing time by executing the write
operations of several commands together after storing
write data in the cache area.
The drive has a self-monitoring analysis reporting
technology (SMART) function, which warns of critical
HDD failures in advance, to realize a full-fledged
implementation of a logging function for detailed failure
analysis. The drive also has a self-test function, a self-
diagnostic function which allows the status of the HDD to
be diagnosed if the system requires it.
(3) Cache function
Temporarily holds data to be read or written to/from
magnetic disks, improve command responses, and
optimizes processing in response to various access
forms from the host.
End-to-end data protection (an error detection function
executed upon any component failure) and a disk-surface-
defect avoidance function ensure data reliability at all
times. Furthermore, the following processes are executed
in the background, which may improve reliability during
continuous long-term operation.
By expanding the data buffer capacity from 16 MB of the
previous model to 32 MB, we improved cache hit rates
and realized high performance.
Furthermore, we realized both high performance and low
power consumption by introducing a multi-level automatic
power saving algorithm and command-driven forcible
power saving as power saving functions.
(1) Background media scan (BMS) function
Performs a full scan of the data area at regular in-
tervals to detect recoverable errors in advance and
automatically recover them.
An optional self-encryption drive (SED) function, which
allows the HDD itself to internally encrypt data, and a data
integrity field (DIF) function, which allows data protection
to be controlled at the system level, are supported.
(2) System area (SA) saving function
Improves the log function by periodically saving
system information on the HDD into the SA, which is
isolated from the user-accessible areas.
5. Conclusion
4.2.2. High functionality, high performance,
and low power consumption
We optimized and improved the following three basic HDD
functions.
We developed a high-performance 2.5-inch enterprise
class HDD with a rotation speed of 15,000 rpm and
an average seek time of 2.7 ms. During development,
we employed new technologies for the mechanical
components, servo control section, and controller firmware
section to enable high reliability and high performance.
Going forward, Toshiba will continue to push forward
with the development of HDDs for the enterprise market
featuring both higher performance and higher quality.
(1) Reordering function
Executes command processing in the shortest possi-
ble period of time by optimizing the execution order of
received commands (up to 128 commands).
Toru
IWAMOTO
Akihiko
MAKITA
Tatsuro
SASAMOTO
Keiichi
YORIMITSU
Storage Products
Div.
Storage Products
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Storage Products
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Storage Products
Div.
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