Hitachi HDS721050CLA362 - 6.0 Specification

HITACHI Deskstar & CinemaStar 7K1000.B & Deskstar E7K1000 Hard Disk Drive specification
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4.5.2 Mechanical positioning
4.5.2.1 Average seek time (without command overhead, including settling)
Command Type
1D
2D/3D
Typical (ms)
Max (ms)
Typical (ms)
Max (ms)
Read
14.0
14.7
8.5
9.2
Write
15.0
15.7
9.5
10.2
Read (Quiet Seek mode)
14.0
14.7
14.0
14.7
Write (Quiet Seek mode)
15.0
15.7
15.0
15.7
Table 8 Mechanical positioning performance
The terms “Typical” and “Max” are used throughout this specification with the following meanings:
Typical. The average of the drive population tested at nominal environmental and voltage conditions.
Max. The maximum value measured on any one drive over the full range of the environmental and voltage
conditions. (See Section 6.2, “Environment” on page 24 and Section 6.3, “DC Power Requirements” on
page 26.)
Seek time is measured from the start of the motion of the actuator to the start of a reliable read or write
operation. "Reliable read or write" implies that error correction/recovery is not used 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) (Tn
in
+ Tn
out
)
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
4.5.2.2 Full stroke seek (without command overhead, including settling)
Command Type
1D
2D/3D
Typical (ms)
Max (ms)
Typical (ms)
Max (ms)
Read
27.0
30.0
15.1
17.7
Write
28.0
31.0
16.1
18.7
Read (Quiet Seek mode)
27.0
30.0
27.0
30.0
Write (Quiet Seek mode)
28.0
31.0
28.0
31.0
Table 9 Full stroke seek time
Full stroke seek is measured as the average of 1000 full stroke seeks with a random head switch from both
directions (inward and outward).