what part hold me back that not letting push cpu go over 3.6gh

[htnt]

Im currently running core 2 extreme 6800 with Asus p5k-delux/wifi motherboard and 4 gb ram ( comebine 2gb from consair and 2gb from kingston ). As of now, I tried everything but I cant get my cpu run stable at 3.54+ ghz... I think voltage hold me back so what voltage should i set for 3.6 ghz over ?

So I need your advise to get cpu run at 3.8 or 3.9ghz ... thx

[XDanger]

http://www.hardforum.com/showthread.php?t=1138241

Are you testing your memory?

Are you using the cooler that came with the cpu?