Hitachi HTS541660J9SA00, HTS541640J9SA00 manual Performance characteristics, Command overhead

Travelstar 5K160 (SATA) Hard Disk Drive Specification

4.4Performance characteristics

Drive performance is characterized by the following parameters:

Command Overhead

Mechanical Positioning

Seek Time

Latency

Data Transfer Speed

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.

The following table gives a typical value for each parameter. The detailed descriptions are found in section 5.0.

Function
Average Random Seek Time - Read (ms)	11
Average Random Seek Time - Write (ms)	13
Rotational Speed (RPM)	5400
Power-on-to-ready (sec)	3.5
Command overhead (ms)	1.0
Disk-buffer data transfer (Mb/s) (max)	540
Buffer-host data transfer (Gbit/s) (max)	1.5

Table 4. Performance characteristics

4.4.1Command 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.

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