I have two servers of identical spec (bought at the same time), except for the drive configuration:
- C: and D: drives are partitions on the same 2 disk RAID 1
- E: is a 2 disk RAID 0
- C: is a 2 disk RAID 1
- D: is a 2 disk RAID 1
- E: is a 4 disk RAID 10
Server A was set up for testing and so only had limited number of drives. Server B is to be used as a live system (and incidentally has more memory and an extra processor).
Compared to Server A, Server B has double the read performance on the E: drive. Other than that though, all the drives are performing worse than the drives on Server A (as tested using SQLIO). For write speed, all of the drives are writing at less than half the rate of Server A.
I'm not certain that the drives are from the same manufacturer, but they are of equivalent spec, so whilst I might expect a certain difference in speed due to manufacturer differences, I wouldn't expect the performance differences that I am seeing, particularly in write speed.
What could be causing this?