+1 for saint's post and the C3 is a big difference too when it comes to OCing and power. You could also consider the AMD Phenom II X2 555, which unlocks to a quad. However it's not 100% chance that you'll unlock. I'd go to a local store for that. I get my 555 at fry's and if it doesn't unlock i return until i get one that does haha it's funny they don't care.