I was looking at Drivespeed a few weeks ago because my NEC 3550A was always spinning hard and loud. It's in a recently built HTPC, so loud isn't desired. After poking around the 'net, seems that Drivespeed is a crap-shoot: works with some drives, not others, and some can work after a firmware flash.
I skipped it and thru in an Asus 1612BL that I had lying around...that thing is dead quiet.
But give Drivespeed a shot, it may work for you.