Intel Xeon E5450 Gaming. Your at 3.5, so it sounds good. It is in the games.
Since the e5450 is a socket lga771 server processor, and there are none or very few gaming boards for that socket, it must be modified before it will work in an lga775 motherboard. Lastly, you may have hit a thermal limit. 12m cache, 3.00 ghz, 1333 mhz fsb.