the motherboard only plays a certain role in OC. you need good ram and hope you got a good chip that will overclock well. some q6600 wont go past 2.5OC some will hit 4gh WC.
But keep in mind you can buy the top of the line i7 and not even break 3ghz stable. It all has to do with the quality of the part when assembled from manufacture. each one is not made the same.