2.8Power specifications

The drive receives DC power (+5V or +12V) through a native SATA power connector. See Figure 4 on page 24.

2.8.1Power 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, using 5.0V and 12.0V 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 reaches operating speed.

• 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 represents the worst-case power consumption, using only random seeks with read or write latency time. This mode is not typical and is provided for worst-case information.

• Read/write power and current

Read/write power is measured with the heads on track, based on a 16-sector write followed by a 32-msec delay, then a 16-sector read followed by a 32-msec delay.

• Operating power and current

Operating power is measured using 40 percent random seeks, 40 percent read/write mode (1 write for each 10 reads) and 20 percent drive idle mode.

• 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 mode.

Table 4:

DC power requirements

 

 

 

 

 

 

 

Power dissipation (watts)

Avg (watts, 25° C)

Avg 5V typ amps

Avg 12V typ amps

 

 

 

 

 

Spinup

 

2.8 (peak)

 

 

 

 

 

Idle*

 

8.0

0.63

0.24

 

 

 

 

Idle* (with offline activity)

8.0

0.63

0.24

 

 

 

 

Operating (40% r/w, 40% seek, 20% inop.)

10.9

0.64

0.33

 

 

 

 

Seeking (random, 20% idle)

10.9

0.59

0.39

 

 

 

 

 

Standby

 

1.5

0.24

0.01

 

 

 

 

 

Sleep

 

1.4

0.24

0.01

 

 

 

 

 

*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.

Barracuda 7200.9 Serial ATA Product Manual, Rev. C

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Seagate ST380811AS, ST3120811AS, ST3120211AS, ST3160211AS, ST3160811AS, ST380211AS, ST340211AS manual Power specifications