Disk Response Time

In this test IOMeter is sending a stream of requests to read and write 512-byte data blocks with a request queue of 1 for 10 minutes. The total number of requests processed by the HDD is over 60 thousand, so we get a sustained response time that doesn’t depend on the HDD’s buffer size.

The read response time depends not only on the recording density and rotation speed of an HDD’s platters, but also on the speed of the heads, the number of servo marks per platter and some other important factors. As a result, the Hitachi has a very slow response. The Samsung is not very good, either, and is 0.5 milliseconds inferior to the 320GB Western Digital. The new 500GB model from Western Digital is superb in this test: its read response time of 16 milliseconds is very, very good.

The average write response depends mostly on the efficiency of deferred write algorithms. And again, both drives from Western Digital are in the lead: excellent mechanics is backed up by good firmware algorithms in the 500GB model which wins this test. The opponents are worse but not hopeless.