go to the bios and check the clock speeds from there. If they show up 1 ghz lower in there too then start oc'ing. And keep an eye on the temps when oc'ing, it should easily get to the default speeds, but it never hurts to be carefull.
And a silly question, but u know that it should be running at 1.8 Ghz or 2.0 Ghz, not 3.0 Ghz?