Datasheet

4.3 Performance characteristics

Drive performance is determined by the following parameters:

y Command overhead

y Mechanical positioning

- Seek time

- Latency

y Data transfer speed

y Buffering operation (Look ahead/Write cache)

Note: All the above parameters contribute to drive performance. Other parameters also contribute to the

performance of the actual system. This specification describes only the characteristics of the drive, not

the system throughput which depends on the system and the application.

The following table gives a typical value of each parameter. Detailed descriptions follow in the next

sections.

Refer to CFA SpecificationDisk-host data transfer

37.8–58.6 Mbit/sDisk-buffer data transfer

1 msCommand Overhead

1.5 secPower On To Ready

3600 RPMRotational speed

13 ms

Average Random Seek Time for

Write

12 ms

Average Random Seek Time for

Read

TypicalFunction

Figure 3. Performance parameters

4.3.1 Command overhead

Command overhead time is defined as the total time from the receipt of the command by the drive to the

start of motion of the actuator.

4.3.2 Mechanical positioning

4.3.2.1 Average Seek Time (Including Settling)

1513Write

1412Read

Max (ms)Typical (ms)Command Type

Figure 4. Mechanical positioning performance

Headings "Typical" and "Max" are given throughout the performance specification. Typical means the

average of the drive population tested at nominal environmental and voltage conditions. Max means the

maximum value measured on any one drive over the full range of the environmental and voltage

Hard disk drive specification for DSCM-11000/-10512/-10340