M
OMENTUS
T
HIN
SATA P
RODUCT
M
ANUAL
, R
EV
. G
6
D
RIVE
S
PECIFICATIONS
2.2
P
HYSICAL ORGANIZATION
Drive model
Read/write heads
Number of discs
ST500LT012, ST500LT015 and ST500LT025
2
1
ST320LT012, ST320LT015 and ST320LT025
ST250LT012, ST250LT015 and ST250LT025
1
2.3
R
ECORDING AND
I
NTERFACE
T
ECHNOLOGY
Recording method
Perpendicular
Recording density
1958 Kb/in
Track density
360 ktracks/in avg
Areal density
705 Gb/in
2
avg
Spindle speed
5400 RPM +/- 0.2%
Sustained data transfer rate
100 MB/s max
I/O data-transfer rate
300 MB/s max
2.4
P
HYSICAL
C
HARACTERISTICS
Height
6.8 +/- 0.2 mm (0.370 +/-.008 in)
Width
69.85 +/- 0.25 mm (2.750 +/- 0.010 in)
Length
100.35 +0.20 / -0.25 mm (3.951 +0.008 / -0.010 in)
Typical weight
95 g (0.209 lb)
Cache buffer
16 MB (16,192 KB)
2.5
S
EEK 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.
Interface
Serial ATA (SATA)
All models
Table 2
Typical seek times
Typical seek times (ms)
Read
Track-to-track
1.5
Average
12.0
Average latency
5.6
N
OTE
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.
