Performance Characteristics; Command Processing; Average Seek Time (Including Settling) - IBM DTCA-23240 - Travelstar 3.2 GB Hard Drive Specifications

3.3 Performance Characteristics

File performance is characterized by the following parameters:
Command Overhead
Mechanical Positioning
Seek Time
Latency
Data Transfer Speed
Buffering Operation
Note: All the above parameters contribute to a file performance. There are other parameters which con-
tribute to the performance on the actual system. This specification tries to define the essential file character-
istics, not the system throughput which is dependent on the system and the application.
The following table gives a typical value of each parameter. The detail descriptions are followed in the next
sections.
Function
Average Random Seek Time For Read
Average Random Seek Time For Write
Rotational Speed
Power On To Ready
Command Overhead
Disk-Buffer Data Transfer
Buffer-Host Data Transfer
Figure 5. Performance Parameter

3.3.1 Command Processing

Command overhead time is defined as the total time from when the command is received by the drive to the
start of motion of the actuator.

3.3.2 Average Seek Time (Including Settling)

Command Type
Read
Write
Figure 6. Mechanical Positioning Performance
'Typical' and 'Max' are given throughout the performance specification by;
Typical Average of the drive population tested at nominal environmental
and voltage conditions.
Max Maximum value measured on any one drive over the full range of the environmental and
voltage conditions. (See section on Environment and D.C. Power Requirements.)
10
O E M Specifications of DTCA-2xxxx 2.5 inch H D D
Typical
13 msec
14 msec
4000 rpm
2.8 sec
1.0 msec
83.4 - 51.7 Mbit/sec
16.6 MB/sec (PIO Mode-4)
33.3 MB/sec (Ultra D M A Mode-2)
Typical
13 msec
14 msec
Max
16 msec
17 msec