I overclocked my QQ6600 Core 2 Quad (G0 Stepping Revision) to 3.0 Ghz by setting the frequency to 333mhz, and the multiplier to 9. I changed the RAM ratio to 2.00D (which is apparently 400Mhz x 2.00 right? According to the little explanation in my gigabyte bios at least.)
When I open up properties on My Computer it says:
"Core(TM)2 Quad CPU Q6600 @ 2.40GHz 3.00GHz"
I believe CPU-Z is reading it lower because my processor slows down (likely due to a mobo automatic function?) the multiplier when it is not under heavy use, because AFTER I start running WOW and a few other programs it will shoot up to the 3.0Ghz and x9 multiplier.