Seagate Desktop HDD Product Manual, Rev. J
9
www.seagate.com
Drive Specifications
2.5
Physical characteristics
2.6
Seek 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 5000 measurements of seeks between random
tracks, less overhead.
Maximum height
3TB, 2TB and 1.5TB
26.1mm / 1.028 in
1TB, 750GB, 500GB, 320GB, 250GB
19.98mm / 0.787 in
Maximum width (all models)
101.6mm / 4.0 in (± 0.010 in)
Maximum length (all models)
146.99mm / 5.787 in
Typical weight
3TB and 2TB
626g / 1.38 lb
1.5TB
535g / 1.18 lb
1TB and 750GB
400g / 0.88 lb
500GB, 320GB, 250GB
415g / 0.92 lb
Cache buffer
3TB, 2TB, 1.5TB, 1TB, 750GB
64MB (64,768kb)
500GB, 320GB and 250GB
16MB (16,384kb)
Typical seek times (ms)
Read
Write
Track-to-track
1.0
1.2
Average
8.5
9.5
Average latency
4.16
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.
