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 Western Digital Caviar Black has the best response time at reading, being just a fraction of a millisecond better than its Blue opponent. This pair looks good in this test. The Seagate and Samsung are more than 1 millisecond behind. The 5400rpm drive is lagging behind. It is about 1 millisecond worse than the closest opponent and more than 2 milliseconds worse than the leader.
The Samsung is the best drive at writing. It is followed by WD’s Caviar Black and Caviar Blue drives that have similar results. The Green drive from WD is only 1 millisecond worse than its mates because write requests are saved into the drive’s cache. The Seagate’s result of 30 milliseconds is quite a shock. Such a high value could be explained by the drive’s doing write verification (by reading data it has written to check its integrity), but this technology would only be enabled in harsh thermal conditions or at strong vibration. We have our drives working in very comfortable conditions with effective cooling, so there is no need for additional self-control. We just can’t understand the odd behavior of the Seagate Barracuda 7200.11.