Performance Characteristics; Command Overhead; Mechanical Positioning; Table 5: Performance Characteristics - Hitachi HTS541010G9AT00 - Travelstar 100 GB Hard Drive Specifications

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 (Look ahead/Write cache)
All the above parameters contribute to drive performance. There are other parameters that contribute to the perfor-
mance of the actual system. This specification tries to define the bare drive characteristics, not system throughput,
which depends on the system and the application.

Table 5: Performance characteristics

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 (Gbps)
4.4.1 Command overhead
Command overhead is defined as the interval from the time that a drive receives a command to the time that the
actuator starts it's motion.

4.4.2 Mechanical positioning

4.4.2.1 Average seek time (including settling)

Table 6: Mechanical positioning performance

Command type
Random track @ read
Random track @ write
Function
Typical (ms) Max (ms)
12
13
Travelstar 5K100 (Serial ATA) Hard Disk Drive Specification
12
13
5400
3.5
1.0
493 max
1.5
14
15
16