Hitachi HTS543232L9SA00 Computer Drive User Manual


 
5K320 SATA OEM Specification
19
4.4.2 Mechanical positioning
4.4.2.1 Average seek time (including settling)
Command Type Typical (ms) Max. (ms)
Read 12 14
Write 13 15
Table 5. Mechanical positioning performance
Typical and Max. are defined throughout the performance specification as follows:
Typical
Average of the drive population tested at nominal environmental and voltage conditions.
Max.
Maximum value measured on any one drive over the full range of the environmental and
voltage conditions. (See section 6.1, "Environment" and section 6.2, "DC power
requirements" )
The seek time is measured from the start of motion of the actuator to the start of a reliable read or write
operation. A reliable read or write operation implies that error correction/recovery is not employed to
correct arrival problems. The Average Seek Time is measured as the weighted average of all possible
seek combinations.
max.
(max. + 1 – n)(Tn
in
+ Tn
out
)
n=1
Weighted Average = ––––––––––––––––––––––––––––
(max. + 1)(max)
Where: max. = maximum seek length
n = seek length (1-to-max.)
Tn
in
= inward measured seek time for an n-track seek
Tn
out
= outward measured seek time for an n-track seek
4.4.2.2 Full stroke seek
Command Type Typical (ms) Max. (ms)
Read 20.0 25.0
Write 21.0 26.0
Table 6. Full stroke seek time
Full stroke seek time in milliseconds is the average time of 1000 full stroke seeks.
4.4.2.3 Single track seek time (without command overhead, including
settling)
Command Type Typical (ms) Maximum (ms)
Read 1.0 2.0
Write 1.1 2.2
Table 7. Single track seek time
Single track seek is measured as the average of one (1) single track seek from every track in both
directions (inward and outward).
4.4.2.4 Average latency
Rotational Speed
(RPM)
Time for one revolution
(ms)
Average Latency
(ms)
5400 11.1 5.5
Table 8. Latency time