Hitachi 7K100 Hard Drive Specifications - Page 27

Performance characteristics

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4.4 Performance characteristics Drive performance is characterized by the following parameters: • Command overhead • Mechanical head positioning - Seek time - Latency • Data transfer speed • Buffering operation (read ahead/write cache) Note: All the above parameters contribute to drive performance. There are other parameters that contribute to the performance of the actual system. This specification defines the essential characteristics of the drive. It does not include system throughput which is dependent on the system and the application. The following table gives a typical value for each parameter. The detailed descriptions are found in Section 5.0, "Data integrity" beginning on page 17. Table 4: Performance characteristics Function Average random seek time - read (ms) Average random seek time - write (ms) Rotational speed (RPM) Power-on-to-ready (sec) Command overhead (ms) Disk-buffer data transfer (Mb/s) Buffer-host data transfer (MB/s) 10 11 7200 4.0 1.0 267 - 629 100 4.4.1 Command overhead Command overhead time is defined as the interval from the time that a drive receives a command to the time that the actuator starts its motion Travelstar 7K100 Hard Disk Drive Specification 13

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Travelstar 7K100 Hard Disk Drive Specification
13
4.4
Performance characteristics
Drive performance is characterized by the following parameters:
Command overhead
Mechanical head positioning
-
Seek time
-
Latency
Data transfer speed
Buffering operation (read ahead/write cache)
Note:
All the above parameters contribute to drive performance. There are other parameters that contribute to the
performance of the actual system. This specification defines the essential characteristics of the drive.
It does not
include system throughput which is dependent on the system and the application.
The following table gives a typical value for each parameter. The detailed descriptions are found in Section 5.0,
“Data integrity” beginning on page 17.
4.4.1
Command overhead
Command overhead time is defined as the interval from the time that a drive receives a command to the time that
the actuator starts its motion
Table 4: Performance characteristics
Function
Average random seek time - read (ms)
10
Average random seek time - write (ms)
11
Rotational speed (RPM)
7200
Power-on-to-ready (sec)
4.0
Command overhead (ms)
1.0
Disk-buffer data transfer (Mb/s)
267 - 629
Buffer-host data transfer (MB/s)
100