IBM DTCA-24090 Hard Drive Specifications - Page 18

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 contribute to the performance on the actual system. This specification tries to define the essential file characteristics, 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 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 DMA Mode-2) 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 13 msec 14 msec Max 16 msec 17 msec 'Typical' and 'Max' are given throughout the performance specification by; Typical Max Average of the drive population tested at nominal environmental and voltage conditions. 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 OEM Specifications of DTCA-2xxxx 2.5 inch H D D