Seagate ST31000640AS, ST31000340AS manual Physical characteristics, Seek time, Start/stop times

2.4	Physical characteristics
Maximum height (1000-500 GB models)		26.1 mm (1.028 inches)
Maximum width		101.6 mm (4.000 +/- 0.010 inches)
Maximum length		146.99 mm (5.787 inches)
Typical weight
	1000 GB models	677 grams (1.493 lbs)
	750 GB models	633 grams (1.396 lbs)
	500 GB models	543 grams (1.199 lbs)
Cache buffer
	ST31000340AS, ST3750330AS and ST3500320AS	32	Mbytes (32,768 kbytes)
	ST31000640AS, ST3750630AS and ST3500620AS	16	Mbytes (16,384 kbytes)
	ST3500820AS	8	Mbytes (8,192 kbytes)

2.5Seek 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.

Typical seek times (msec)	Read	Write
Track-to-track (1000 GB & 750 GB models)	<1.0	<1.2
Track-to-track (500 GB models)	<0.8	<1.0
Average	<8.5	<9.5
Average latency:	4.16

*Measured in performance mode.

**Measured in quiet 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.

2.6	Start/stop times
		1000 GB	750 GB	500 GB
		Models	Models	Models
Power-on to Ready (sec)		20 (max)
Power-on to Ready (sec) (2.0 Amp Code Option)		17 (max)
Standby to Ready (sec)		15 (max)		14 (max)
Ready to spindle stop (sec)		10 (max)

Barracuda 7200.11 Serial ATA Product Manual, Rev. C 9