Performance Characteristics - Hitachi 7K320 - Travelstar Mobile Hard Drive Specifications

4.4

Performance 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/Write (ms)
Rotational Speed (RPM)
Power-on-to-ready (sec)(Typical)
Command overhead (ms)
Disk-buffer data transfer (Mb/s) (max)
Buffer-host data transfer (Gbit/s) (max)
Table 4. Performance characteristics
Command overhead
4.4.1
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.
12
7200
4.0
1.0
1136
1.5/3.0
Page 18 of 176
7K320 SATA OEM Specification