in the United States and/or other countries. Momentus, SeaTools and SeaTDD are either trademarks or
registered trademarks of Seagate Technology LLC or one of its affiliated companies in the United States
and/or other countries. All other trademarks or registered trademarks are the property of their respective
owners.
One gigabyte, or GB, equals one billion 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 purposes. Actual quantities will vary based on various factors, including file
size, file format, features and application software. 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.
• 1,000 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 Dr ive Defense, D ata Defense and Diagnosti c 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.
2
Momentus 7200.3 SATA Product Manual, Rev. B
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 transiti o n from pa rallel ATA easy by providi ng legacy sof twar e suppo rt. S erial
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 cont ai ns a set of registe rs that sha dow the conte nt s of the trad iti onal device r egisters, 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.
Momentus 7200.3 SATA Product Manual, Rev. B
3
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 the
ST9320421AS, ST9320421ASG, ST9250421AS, ST9250421ASG, ST9200421AS, ST9200423ASG,
ST9160411AS, ST9 16041 1ASG, S T912041 1AS, ST91 2041 1ASG, S T980411AS and ST980411ASG m odels.
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.
T a ble 1: Drive speci ficat ion s
Drive speci fication
Formatted Gbytes
(512 bytes/sector)*
Guaranteed sectors625,142,448488,397,168390,721,968312,581,808234,441,648156,301,488
Bytes per sector512
Physical read/write heads433221
Discs222111
Cache (Mbytes)16
Recording density in BPI
(bits/inch max)
Track density TPI
(tracks/inch max)
Areal density
(Gbits/inch2 max)
Spindle speed (RPM)7,200
Average latency (msec)4.17
Internal transfer rate
(Gbits/sec max)
I/O data transfer rate
(Gbits/sec max)
ATA data-transfer modes
supported
Height (max)9.5 +/- 0.2 mm (0.374 +/- .0078 inches)
Width (max)69.85 +/- 0.249 mm (2.75 +/- 0.0098 inches)
Length (max)100.33 +/- 0.25 mm (3.95 +/- .010 inches)
Weight (max)110 grams (0.238 lb)105 grams (0.227 lb)
Power-on to ready
(sec typical)
ST9320421AS
ST9320421ASG
32025020016012080
1,334k
190k
253
1.1
3.0
SATA 1.0, Serial ATA Revision 2.6
PIO modes 0–4
Multiword DMA modes 0–2
Ultra DMA modes 0–6
4.0
ST9250421AS
ST9250421ASG
ST9200421AS
ST9200423ASG
ST9160411AS
ST9160411ASG
ST9120411AS
ST9120411ASG
ST980411AS
ST980411ASG
4
Momentus 7200.3 SATA Product Manual, Rev. B
T a ble 1: Drive speci ficat ion s
Drive speci fication
Standby to ready
ST9320421AS
ST9320421ASG
3.0
ST9250421AS
ST9250421ASG
ST9200421AS
ST9200423ASG
(sec typical)
Track-to-track seek time,
1.0
read (msec typical)
Average seek, read
11.0
(msec typical)
Average seek, write
(msec typical)
13.0
Startup current, +5V (max)1.0 amps
Seek power (typical)2.3 watts
Read power (typical)2.1 watts
Write power (typical)2.3 watts
Idle mode, low power
Supports Hotplug operation per Serial A TA Revision
2.6 specification
*One Gbyte equals one billion bytes when referring to hard drive capacity. Accessible capacity may vary depending on operating environment
and formatting.
**During period s of driv e idle, some offline acti vi ty may occ u r accor di ng to th e S. M.A.R .T. spe c ifica tion, w hich may increase acoustic and
power to operational levels.
***Typical notebooks will pull power to th e drive when ente ring S3 and S4; while in the S3 and S4 states, dr ive sleep and drive standby
modes will not contribute to battery power consumption.
ST9320421AS
ST9320421ASG
600,000 software-controlled power on/off cycles
50,000 hard power on/off cycles
600,000 software-controlled power on/off cycles
50,000 hard power on/off cycles
To determine the warranty for a specific drive, use a web browser to access the following web page:
www.seagate.com/support/service/
From this page, click on the “Verify Your Warranty” link. Y ou will be asked to provide the drive serial number, model number (or part number) and country of purchase. The system will display the warranty information for your drive.
Y es (requires COMPRESET from host after a hotplug event)
ST9250421AS
ST9250421ASG
ST9200421AS
ST9200423ASG
ST9160411AS
ST9160411ASG
ST9120411AS
ST9120411ASG
ST980411AS
ST980411ASG
2.2Formatted ca pacity
ModelFormatted capacity*Guaranteed sectors Bytes per sector
ST9320421AS and ST9320421ASG320 Gbytes625,142,448512
ST9250421AS and ST9250421ASG250 Gbytes488,397,168512
ST9200421AS and ST9200423ASG200 Gbytes390,721,968512
ST916041 1AS and ST9160411ASG160 Gbytes312,581,808512
ST912041 1AS and ST9120411ASG120 Gbytes234,441,648512
ST98041 1AS and ST980411ASG80 Gbytes156,301,488512
*One Gbyte equals one billion bytes when referring to hard drive capacity. Accessible capacity may vary depending on operating envir onment
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 48bit addressing support of drives with capacities over 137 Gbytes.
6
Momentus 7200.3 SATA Product Manual, Rev. B
2.3Default logi cal geometr y
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
ST9320421AS and ST9320421ASG42
ST9250421AS and ST9250421ASG32
ST9200421AS and ST9200423ASG32
ST916041 1AS and ST9160411ASG21
ST912041 1AS and ST9120411ASG21
ST98041 1AS and ST980411ASG11
2.5Recording and int er f ac e te ch no l o gy
InterfaceSerial ATA (SA TA)
Recording methodPerpendicular
Recording density BPI (bits/inch max)1,334k
Track density TPI (tracks/inch max)190k
Areal density (Gbits/inch2 max)253
Spindle speed (RPM) (± 0.2%)7,200
Maximu m Internal tr a n sfer rate (Gb i ts/sec)1.1
I/O data-transfer rate (Gbits/sec max)3.0
Interleave1:1
Cache buffer16 Mbytes (16,384 kbytes)
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 in the table 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.
Table 2: Typical seek times
T yp ical seek times (msec)Read
Track-to-track1.0
Average11.0
Full-stroke22.0
Average latency4.17
Note.These drives ar e de si gned to consisten tl y me et t he se ek t imes r epr esente d in thi s manu al. P hysical
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.
8
Momentus 7200.3 SATA Product Manual, Rev. B
2.8Start/stop times
Time to readyTypical
Power-on to Ready (sec)4.08.0
St andby to Ready (sec)3.08.0
Max @ 25°C
2.9Power specifications
The drive receives DC power (+5V) through a native SATA power connector.
2.9.1Power consumption
Power requiremen ts for the dr iv es are listed i n the ta ble on p age 8. Typical power measurements 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 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