ScottPletcher (7/27/2012)
Tempdb drives are much too small. SQL uses tempdb a lot, and you can't afford to run out of tempdb space.I would not dismiss RAID5 for the db data so quickly. Reads are faster on RAID5, although writes are much slower of course. Proper selection here requires more investigation.
I agree that tempdb data should not be on RAID5, since it is a higher % of write vs read.
I don't have the links anymore, but I did quite a bit of research a few years ago and that research pushed me away from RAID 5 to RAID 10 for my database servers.
Best thing I can suggest here is do your research, then make your decision. If I had to support this type of decision now, I'd be back doing my research as I know that just saying this is how it should be you need to know for sure.
Also helps if you can stress test several configurations prior to actual deployment.