3.9Power specifications
The drive receives DC power (+5V) through a native SATA power connector.
3.9.1Power consumption
Power requirements for the drives are listed in the table on page 9. 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
•Seek mode
During seek mode, the read/write actuator arm moves toward a specific position on the disc surface and does not execute a read or write operation. Servo electronics are active. Seek mode power is measured based on three random seek operations every 100 ms. 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
Table 3: | DC power |
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| ST9750423AS, ST9750423ASG, | ST9750422AS, ST9750420AS, |
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| ST9640424AS, ST9640423AS, | ST9750420ASG, ST9500424AS, |
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| and ST9640423ASG, | ST9500423AS and ST9500423ASG |
Power dissipation | +5V input average (25° C) |
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Spinup (max) | 1.0A |
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Seek Average | 1.9W | 2.5W | |
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Write Average | 1.85W | 2.4W | |
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Read Average | 1.6W | 2.1W | |
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Idle, performance* | 1.4W | 2.0W | |
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Idle, active* |
| 0.80W | 0.96W |
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Idle, low power mode* | 0.55W | 0.70W | |
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Standby |
| 0.15W |
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Sleep |
| 0.15W |
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*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.
Momentus Product Manual, Rev. B | 9 |
