In comparision to other pcb's, MrsBytch is correct.
I got my E8400 overclocked (400x9) 3.6GHz solid. (See my config on the left) I could do (456x8) 3.648GHz. Above 456 or 3.65-(1.25V) it was unstable. I didn't fully explore all freq,mult,voltage combos to move beyond that. Onboard GPU could be the restrictive item regardless of what you do there.