I had thought about getting a Q9550 later, but did not want to spend but so much on a new cpu, and got the Q9300. I wish I had stuck to my original plan now. However, this cpu is at 3.2GHz (427fsb). It is currently at 1.2375 volts in bios, and ran 29 hours small ffts in prime95 with no errors, and then 24 hours large ffts with no errors. The vid is 1.2125.
Any lifespan reduction on this cpu with the voltage bump I'm using should be minimal I hope. The box says 1.25v max.
edit to add: I have the same case as you do also.
Edited by TonyLee - 1/17/09 at 1:59pm