Seagate ST3120022AS, ST3120827AS, ST3120026AS Seek time, Start/stop times, Power specifications

2.6Seek time

Seek measurements are taken with nominal power at 25°C ambient temperature. All times are measured 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 3:	Typical seek times
*Typical seek times (msec)		Read	Write
Track-to-track		<1.0	<1.2
Average		8.5	9.5
Average latency		4.16	4.16

*Measured in performance mode

Note. These drives are designed to consistently meet the seek times represented in this manual. Physical 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.

2.7Start/stop times

Power-on to Ready (sec)	10 (max)
Standby to Ready (sec)	10 (max)
Ready to spindle stop (sec)	10 (max)

2.8Power specifications

The drive receives DC power (+5V or +12V) through a native SATA power connector. See Figure 4 on page 20.

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.

Barracuda 7200.7 Serial ATA Product Manual, Rev. N 7