Product manual

Barracuda ATA Family Product Manual, Rev. B 7
1.5 Seek time
Seek measurements are taken with nominal power at 25°C ambient
temperature. All times are measured using drive diagnostics. The spec-
ifications 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.
•
Full-stroke seek time is one-half the time needed to seek from the first
data cylinder to the maximum data cylinder and back to the first data
cylinder. The full-stroke typical value is determined by averaging 100
full-stroke seeks in both directions.
Note.
These drives are designed to consistently meet the seek times rep-
resented in this manual. Physical seeks, regardless of mode (such as
track-to-track and average) are expected to meet or exceed the noted
values. However, due to the manner in which these drives are format-
ted, benchmark tests that include command overhead or measure
logical seeks may produce results that vary from these specifications.
1.6 Start/stop times
Maximum length (mm)
(inches)
147.0
5.78
Typical weight (grams)
(pounds)
550
1.2
Typical seek times (msec) Read Write
Track-to-track 0.9 1.6
Average *8.0/7.6 9.1
Full-stroke *14.5/14.2 *17.5/16.9
Average latency: 4.16 msec — —
*8.0 average read, 14.5 full-stroke read and 17.5 full-stroke write applies
to the ST328040A and ST327240A only.
Power-on to Ready (sec) 12 (typical)
Standby to Ready (sec) 12 (typical)
Ready to spindle stop (sec) 11 (typical)