You need to go to your motherboard's manufacturer website and find out what CPUs are supported and go for the fastest model you can afford. You should also update your board's BIOS before swapping CPUs to avoid a potential compatibility issues. If you can run a Phenom II, then I would suggest going for that over another Athlon series. Honestly though, if you have the $$$ go for a complete overhaul using an Intel i3, i5, i7 CPU. I've started a couple of threads here lately asking about CPUs and Intel is the way to go for MAME these days.
Edited by vram74 (08/19/12 10:11 PM)