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registered trademarks of Seagate Technology LLC or one of its affiliated companies in the United
States and/or other countries. All other trademarks or regis te red tra dem arks a re th e pr operty of their
respective owners.
No part of this publication may be reproduced in any form without written permission of Seagate
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One gigabyte, or GB, equals one billion bytes and one terabyte, or TB, equals one trillion bytes. Your
computer's operating system may use a different standard of measurement and report a lower
capacity. In addition, some of the listed capacity is used for formatting and other functions, and thus
will not be available for data storage. Seagate reserves the right to change, without notice, product
offerings or specifications.
• High instantaneous (burst) data-transfer rates (up to 3.0 Gbits per second).
• Perpendicular recording technology.
• State -of-the-art cache and on-the-fly error-correction algorithms.
• Native Command Queuing (NCQ) with command ordering.
• Full-track multiple-sector transfer capability without local processor intervention.
• 1000 Gs nonoperating shock and 350 Gs of operating shock.
• SeaTools diagnostic software performs a drive self-test that eliminates unnecessary drive returns.
• The 3D Defense System™, which includes Drive Defense, Data Defe nse and Diagnostic Defense, of fers the
industry’s most comprehensive protection for disc drives.
• Support for S.M.A.R.T. drive monitoring and reporting.
• Support for Read Multiple and Write Multiple commands.
Momentus 7200.4 SATA Product Manual, Rev. C1
1.1About the Serial ATA interface
The Serial ATA interface provides several advantages over the traditional (parallel) ATA interface. The primary
advantages include:
• Easy installation and configuration with true plug-and-play connectivity. It is not normally necessary to set
any jumpers or other configuration options .
• Thinner and more flexible cabling for improved enclosure airflow and ease of installation.
• Scalability to higher performance levels.
In addition, Serial ATA makes the transition from parallel ATA easy by providing legacy software support. Serial
ATA was designed to allow you to install a Serial ATA host adapter and Serial ATA disc drive in your current
system and expect all of your existing applications to work as normal.
The Serial ATA interface connects each disc drive in a point-to-point configuration with the Serial ATA host
adapter. There is no master/slave relationship with Serial ATA devices like there is with parallel ATA. If two
drives are attached on one Serial ATA host adapter, the host operating system views the two devices as if they
were both “masters” on two separate ports. This essentially means both drives behave as if they are Device 0
(master) devices.
Note.The host adapter may, optionally, emulate a master/slave environment to host software where two
devices on separate Serial ATA ports are represented to host software as a Device 0 (master) and
Device 1 (slave) accessed at the same set of host bus addresses. A host adapter that emulates a
master/slave environment manages two sets of shadow registers. This is not a typical Serial ATA
environment.
The Serial ATA host adapter and drive share the function of emulating parallel ATA device behavior to provide
backward compatibility with existing host systems and software. The Command and Control Block registers,
PIO and DMA data transfers, resets, and interrupts are all emulated.
The Serial ATA host adapter contains a set of registers that shadow the content s of the traditio nal device regi sters, referred to as the Shadow Register Block. All Serial ATA devices behave like Device 0 devices. For additional information about how Serial ATA emulates parallel ATA, refer to the “Serial ATA: High Speed Serialized
AT Attachment” specification. The specification can be downloaded from http://www.serialata.org.
2Momentus 7200.4 SATA Product Manual, Rev. C
2.0Drive specifications
Unless otherwise noted, all specifications are measured under ambient conditions, at 25°C, and nominal
power.
2.1Specification summary table
The specifications listed in this table are for quick reference. For details on specification measurement or definition, see the appropriate section of this manual.
Table 1: Drive specific ations
Drive specification
Formatted GB (512 bytes/sector)*50032025016012080
Guaranteed sectors976,773,168625,142,448488,397,168312,581,808234,441,648156,301,488
Bytes per sector512
Physical read/write heads43/4221/21
Discs221111
Cache (Mbytes)16
Recording density in BPI (max)1490k
Track density TPI (max)265k
2
Areal density (Gb/in
Spindle speed (RPM)7200
Average latency (msec)4.17
Internal transfer rate (Gb/s max)1.23
I/O data transfer rate (Gb/s max)3.0
ATA data-transfer modes supportedSATA 1.0, Serial ATA Revision 2.6
Height (max)9.5 +/- 0.2 mm (0.370 +/- .008 in)
Width (max)69.85 +/- 0.25 mm (2.750 +/- 0.010 in)
Length (max)100.35 +0.20 / -0.25 mm (3.951 +0 .008 / -0.010 in)
Weight (max)110 grams (0.238 lb)105 grams (0.227 lb)
Power-on to ready (sec typical)4.5
Standby to ready (sec typical)3.0
Track-to-track seek time, read
(ms typical)
Average seek, read (ms typical)11.0
Average seek, write (ms typical)13.0
Startup current, +5V (max)1.0 amps
Seek power (typical)2.2 watts
Read power (typical)2.1 watts
Write power (typical)2.2 watts
Idle mode, low power (typical)0.69 watts
Standby mode0.20 watts (typical)***
Sleep mode0.20 watts (typical)***
Voltage tolerance (including noise)+5V ± 5%
Ambient temperature 0°C to 60°C (operating)
–40°C to 70°C (nonoperating)
Temperature gradient
20°C (operating), 35°C (nonoperating)
(°C per hour max)
Relative humidity5% to 95% (operating and nonoperating
Relative humidity gradient30% per hour max
Wet bulb temperature (°C max)37.7 (operating)
40 (nonoperating)
Altitude, operating–304.8 m to 3048 m (–1000 ft to 10,000
Altitude, nonoperating
–304.8 m to 12,192 m (–1000 ft to 40,000
+ ft)
+ ft)
(meters below mean sea level, max)
Shock, operating (Gs max at 2 msec) 350
Shock, nonoperating
800
(Gs max at 2 msec)
Shock, nonoperating
1,000
(Gs max at 1 msec)
Shock, nonoperating
600
(Gs max at 0.5 msec)
Vibration, operating1.0 G (0 to peak, 5–500 Hz)
Vibration, nonoperating5 Gs (0 to peak, 5–500 Hz)
Drive acoustics, sound power (bels)
Idle**2.3 (typical)
*One Gbyte equals one billion bytes when referring to hard drive capacity. Accessible capacity may vary depending on operating environment
and formatting.
**During periods of drive idle, some offline activity may occur according to the S.M.A.R.T. specification, which may increase acoustic and
power to operational levels.
***Typical notebooks will pull power to the drive when entering S3 and S4; while in the S3 and S4 states, drive sleep and drive standby
modes will not contribute to battery power consumption.
4Momentus 7200.4 SATA Product Manual, Rev. C
2.2Formatted capacity
ModelFormatted capacity*Guaranteed sectors Bytes per sector
ST9500420AS and ST9500420ASG500 Gbytes976,773,168512
ST9320423AS and ST9320423ASG320 Gbytes625,142,448512
ST9250410AS and ST9250410ASG250 Gbytes488,397,168512
ST9160412AS and ST9160412ASG160 Gbytes312,581,808512
ST9120410AS and ST9120410ASG120 Gbytes234,441,648512
ST980412AS and ST980412ASG80 Gbytes156,301,488512
*One Gbyte equals one billion bytes when referring to hard drive capacity. Accessible capacity may vary depending on operating environment
and formatting.
2.2.1LBA mode
When addressing these drives in LBA mode, all blocks (
sectors) are consecutively numbered from 0 to n–1,
where n is the number of guaranteed sectors as defined above.
See Section 4.3.1, "Identify Device command" (words 60-61 and 100-103) for additional information about 48-
bit addressing support of drives with capacities over 137 Gbytes.
2.3Default logical geometry
CylindersRead/write headsSectors per track
16,3831663
LBA mode
When addressing these drives in LBA mode, all blocks (sectors) are consecutively numbered from 0 to n–1,
where n is the number of guaranteed sectors as defined above.
2.4Physical organization
Drive modelRead/write headsNumber of discs
ST9500420AS and ST9500420ASG42
ST9320423AS and ST9320423ASG3/42
ST9250410AS and ST9250410ASG21
ST9160412AS and ST9160412ASG21
ST9120410AS and ST9120410ASG1/21
ST980412AS and ST980412ASG11
Momentus 7200.4 SATA Product Manual, Rev. C5
2.5Recording and interface technology
InterfaceSerial ATA (SATA)
Recording methodPerpendicular
Recording density BPI (bits/inch max)1490k
Track density TPI (tracks/inch max)265k
Areal density (Gbits/inch2 max)394
Spindle speed (RPM) (± 0.2%)7200
Maximum Internal transfer rate (Gbits/sec)1.23
I/O data-transfer rate (Gbits/sec max)3.0
Interleave1:1
Cache buffer16 Mbytes (16,384 kbytes)
Seek measurements are taken with nominal power at 25°C am bient temperature. All times are measured using
drive diagnostics. The specifications in the table below are defined as follows:
• Track-to-track seek time is an average of all
• Average seek time is a true statistical random average
random tracks, less overhead.
Table 2: Typical seek times
Typical seek times (msec)Read
Track-to-track1.5
Average11.0
Full-stroke22.0
Average latency4.17
Note.These drives are designed to consistently meet the seek times represented in this manual. Physical
seeks, regardless of mode (such as track-to-track and average), are expected to meet the noted
values. However, due to the manner in which these drives are formatted, benchmark tests that
include command overhead or measure logical seeks may produce results that vary from these
specifications.
possible single-track seeks in both directions.
of at least 5000 measurements of seeks between
2.8Start/stop times
Time to readyTypical
Power-on to Ready (sec)4.55.0
Standby to Ready (sec)3.03.5
Max @ 25°C
Momentus 7200.4 SATA Product Manual, Rev. C7
2.9Power specifications
The drive receives DC power (+5V) through a native SATA power connector.
2.9.1Power consumption
Power requirements for the drives are listed in the t ab le on
page 8. T ypi cal powe r measur ements are based on
an average of drives tested, under nominal conditions, at 25°C ambient temperature.
• Spinup power
Spinup power is measured from the time of power-on to the
time that the drive spindle reaches operating speed.
• Seek mode
During seek mode, the read/write actuator arm moves towar
d a specific position on the disc surface and does
not execute a read or write operation. Servo electronics a re active . Seek m ode p ower is measur ed based on
three random seek operations every 100 msecs. This mode is not typical.
• Read/write
Read/write power is measured with the heads on track, ba
power and current
sed on three 63 sector read or write operations
every 100 msecs.
• Idle mode power
Idle mode power is measured with the drive up to speed, with
servo electronics active and with the heads in
a random track location.
• Standby mode
During Standby mode, the drive accepts commands, but th