All depends on how fast you can throw it.
I know a pitcher can get it up to 96mph, though I don't know how fast it'll spin at that point.
---
Anyhow, RPMs are not a measure of a drive speed.
All that does is lower seek times.
What really counts is the mechanical transfer speed in MB/sec ... this is the speed beyond the cache (which is also pointless since the bus sucks/fills the cache in no time) which makes the drive crawl to a lot slower speed.
RPMs are about as effective at judging the speed of a drive as GHz is for comparing all the CPUs made in the world.