I've been reading about 10k drives being able to run 166 transactions per second vs 250/sec on 15k drives, which in both cases is just the number of rotations per second. What does this really mean for my DB though? If I buy a 15k drive, can I expect to write 250 rows to a table per second, or is it just the theoretical limit due to the atomic nature of an ACID database?
The raid part (from the title) is: if I have a series of 10k drives (e.g. 4 of them) in a raid 10, can I expect to get 2 times the amount of transactions per second (assuming I have nonvolatile cache on the raid controller)? Or, does the number stay exactly the same?
One final thing, how much theoretical gain in trans/sec will I have (when a raid 10), if I move from 10k drives to 15k drives?