Seagate U7 ST3120020A, Product Manual

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U7 Product Manual, Rev. D 9
2.9.1 Power consumption
Power requirements for the drives are listed in the table on page 10. 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.