Verify in your bios setting, the proper cpu setting. usually the multipler is off and thus reflects a lower cpu rating, look at the FSB, etc. save it upon exit. You may have to reboot to be 100% it kept the new setting. This is the 1st area to look into.
good luck -----Willy
My computer, which I built approx 1 year ago, is suddenly displaying the speed of my AMD Athlon 1.2GHZ as 900MHZ. How can this be corrected ??