Hitachi travelstar hds723020bla642 用户手册
7K200 SATA OEM Specification
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4.4 Performance characteristics
Drive performance is characterized by the following parameters:
Command Overhead
Mechanical Positioning
Mechanical Positioning
Seek Time
Latency
Latency
Data Transfer Speed
Buffering Operation (Look ahead/Write Cache)
Buffering Operation (Look ahead/Write Cache)
Note: All the above parameters contribute to drive performance. There are other parameters which
contribute to the performance of the actual system. This specification defines the essential characteristics
of the drive. This specification does not include the system throughput as this is dependent upon the
system and the application.
contribute to the performance of the actual system. This specification defines the essential characteristics
of the drive. This specification does not include the system throughput as this is dependent upon the
system and the application.
The following table gives a typical value for each parameter. The detailed descriptions are found in
section 5.0.
section 5.0.
Function
Average Random Seek Time - Read (ms)
10
Average Random Seek Time - Write (ms)
11
Rotational Speed (RPM)
7200
Power-on-to-ready (sec)(Typical)
4.0
Command overhead (ms)
1.0
Disk-buffer data transfer (Mb/s) (max)
876
Buffer-host data transfer (Gbit/s) (max)
1.5/3.0
Table 4. Performance characteristics
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.
time that the actuator starts its motion.