Performance measures of hard disks / Important measures used for finding the hard disk drive performance / The major performance measures of a HDD
What are the performance measures of hard disks?
Function of a hard disk
|Figure 1 - internal component of a hard disk drive|
How does a hard disk drive function?
- Read-write head is positioned over the right track where the required data might be stored.
- Platters are rotated to bring the right sector under the read-write head.
- The data transfer begins at this point.
Various performance measures of hard disk
- Disk capacity,
- Access time,
- Data-transfer rate
- Power consumption and Shock resistance.
- Seek time – the time for repositioning the arm so that the read-write head can be positioned over the correct track. [Average seek time for Seagate hard disk drive Barracuda 7200.9 is 11 ms approximately]
- Rotational latency time – the time spent for the required sector to appear under the read-write head. [Typical rotational latency for hard disk drive with the speed of 7200 rpm is 4.17 ms approximately]