E7400

what motherboard?

I have a e7200 on a xfx 780i and all that I got to say is good luck, they can be a pain to hit high clocks due to the goop that Greedtel used instead of fluxless solder between the cpu core and the metal cap. It hurts overclocking enough to limit most peoples efforts. If you got a cheap G31 or newer board you might get 3.2-3.6ghz tops. Be stingy with the volts to keep the temps down or it will get hot and be crash/random restart happy.