Hitachi HDS721050CLA362 - Table 114 Streaming Performance Parameters Log; Table 115 Sector Time Array Entry (Linearly Interpolated); Table 116 Position Array Entry (Linearly Interpolated); Table 117 Access Time Array Entry (Linearly Interpolated)

HITACHI Deskstar & CinemaStar 7K1000.B & Deskstar E7K1000 Hard Disk Drive specification
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11.18.7 Streaming Performance log
Table 113 defines the format of the log returned by the Read Log Ext command, when the LBA Low register is
20h. This data set is referred to as the Streaming Performance Parameters log, the length of which (in sectors)
is statically indicated in Read Log Ext log address 00h (Log Directory).
The host should base its calculations on the larger of its Typical Host Interface Sector Time and the device
reported Sector Time values, and on the sum of the device reported Access Time values and any additional
latency that only the host is aware of (e.g. host command overhead, etc.).
Description
Bytes
Stream Performance Parameters log version
2
K, Number of Regions in Sector Time Array
2
L, Number of Positions in Position Array
2
M, Number of Position-differences in Access Time Array
2
Sector Time Array
K*8
Position Array
L*8
Access Time Array
M*4
Reserved
Table 113 Streaming Performance Parameters log
Description
Bytes
LBA of reference location (LBA(7:0)...LBA(47:40))
n-(n+5)
(Identify Device words (99:98))/65536 time units per sector at the reference location
(n+6)-(n+7)
Table 114 Sector Time Array Entry (Linearly Interpolated)
Description
Bytes
LBA of start of region (LBA(7:0)...LBA(47:40))
n-(n+5)
Position number in the range 0...32767
(n+6)-(n+7)
Table 115 Position Array Entry (Linearly Interpolated)
Description
Bytes
Difference in position from last stream access to new stream access
n-(n+1)
Time that may be required to begin access at new stream access position, in
(Identify Device words (99:98))/256 time units
(n+2)-(n+3)
Table 116 Access Time Array Entry (Linearly Interpolated)