Seagate, Seagate Technology and the Wave logo are registered trademarks of Seagate
Technology LLC in the United States and/or other countries. Momentus, SeagateSeaBOARD, SeaFONE, SeaTDD, and SeaTools are either trademarks or registered trademarks of Seagate Te chnolog y LLC or one of it s af filiate d comp a nies in the United States a nd/
or other countries. All other trademarks or registered trademarks are the property of their
respective owners.
One gigabyte, or GB, equals one billion bytes and one terabyte, or TB, equals one trillion
bytes when referring to hard drive capacity. Accessible capacity may vary depending on
operating environment and formatting. Quantitative usage examples for various applications
are for illustrative p urpo ses. Actual quan tities w ill vary based on vari ou s factors, including fi le
size, file format, features and application software. Seagate reserves the right to change,
without notice, product offerings or specifications.
Momentus 5400.2 Blade Server Product Manual, Rev. B
• State-of-the-art cache and on-the-fly error-correction algorithms.
• Full-track multiple-sector transfer capability without local processor intervention.
• 800 Gs nonoperating shock and 250 Gs operating shock.
• SeaTools™ diagnostic software performs a drive self-test that eliminates unnecessary drive returns.
• The 3D Defense S ystem ™, which i nclude s Drive D efen se, Dat a 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.
• Support for autodetection of master/slave drives that use cable select (CSEL).
®
Figure 1. Momentus 5400.2 PATA disc drive
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Momentus 5400.2 Blade Server Product Manual, Rev. B
Momentus 5400.2 Blade Server Product Manual, Rev. B
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2.0Drive specifications
Unless otherwise noted, all specifications are measured under ambient conditions, at 25°C, and nominal
power. For convenience, the phrases the drive and this drive are used throughout this manual to indicate
ST9120821AB, ST9100824AB, ST98823AB, ST96812AB, and ST94813AB model drives.
2.1Specification summary
The specifications listed in this table are for quick reference. For details on specification measurement or
definition, see the appropriate section of this manual.
*One Gbyte equals one billion bytes when referring to hard drive capacity. Accessible capacity may vary depending on operating environment
and formatting.
2.3Default logi cal 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.
Momentus 5400.2 Blade Server Product Manual, Rev. B
2.5Recording and interfac e technology
TechnologySpecification
InterfaceParallel ATA
Recording methodRLL 0,11
Recording density BPI (bits/inch typical)778k
Track density TPI (tracks/inch typical)126k
Areal density (Gbits/inch2 max)98.2
Spindle speed (RPM) (± 0.2%)5,400
Internal data-transfer rate OD (Mbytes/sec max)42
I/O data-transfer rate (Mbytes/sec max)100 (Ultra DMA mode 5)
Interleave1:1
Cache buffer8 Mbytes (8,192 kbytes)
2.6Physical characteristics
Height(mm)
(inches)
Width(mm)
(inches)
Length(mm)
(inches)
Typical weight(grams)
(pounds)
9.5 +/–0.2
0.374 +/–0.008
69.85 +/–0.25
2.750 +/–0.010
100.2 +/–0.25
3.945 +/–0.010
100
0.22
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2.7Seek time
Seek measurem ent s a re t ake n wi th nom inal po w er a t 25 °C amb ient temperature. All tim es a re m easu red using
drive diagnostics. The specifications below are defined as follows:
• Track-to-track seek time is an average of all possible single-track seeks in both directions.
• Average seek time is a true statistical random average of at least 5,000 measurements of seeks between
random tracks, less overhead.
T yp ical seek times (msec)*Read Write
Track-to-track1.01.5
Average12.514.5
Full-stroke22.024.0
Average latency5.565.56
*Measured in performance mode
Note.These drives are d esig ne d t o con si s ten tly me et th e see k t i mes re pre se nt ed in th i s m anu al. P hysi ca l se ek s,
regardless of mode (such as track-to-track and average), are expected to meet or exceed 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.
2.8Time to ready
Time to readyTypical
Power-on to Ready (sec)3.58.0
St andby to Ready (sec)3.08.0
Max @ 25°C
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Momentus 5400.2 Blade Server Product Manual, Rev. B
2.9Power specifications
The drive receives DC power (+5V) through the interface connector.
2.9.1Power consumption
Power requiremen ts for the dr i ves are lis ted in the ta bl e on p age 8 . Typical power measurements are based on
an average of drives tested, under nominal conditions, using 5.0V input voltage at 25°C ambient temperature.
• Spinup power
Spinup power is measured from the time of power-on to the time that the drive spindle re aches operating speed.
• Seek mode
During seek mod e, the read /write actuator arm move s toward a spe cific positi on on the d isc surface and does
not execute a read or write operati on. Servo ele ctronics ar e acti ve. Seek mode power is mea sure d based on
three random seek operations every 100 msecs. This mode is not typical.
• Read/write power and current
Read/write power is measured with the heads on track, based 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 the drive is not spinning, and the servo and read/
write electronics are in power-down model