I have an Opty 148 on air that is running fine for me, but I thnk I want to upgrade my CPU (but not fork out on a new M/B etc). I have been looking around to try to see what the difference is between the FX CPUs and the standard 64 / Opterons. True mine only has 1 core and I would probably look at a FX60 which would give me an extra core, but what would be the difference between that and a standard Athlon64?