This may actually have something to do with power saving features, you should try running a multi-threaded app other than a stress test like a good video converter, you could get a trial of Sony Vegas from Sony.com and just put in some random sample videos and render them with Xvid or DivX, Xilisoft Video Converter uses all your CPU cores and allows you to enable and disable them, so in conclusion you should check if using the CPU normally would stress your CPU, rather than stress tests, some times there are a lot of problems with power saving features like one I had with my GT 240 which ran at 100MHz in non DirectX games or when I was watching and HD movie, it would lag, I disabled power saving so that it always ran at it's max clocks and it solved the problems, you can't do this with an Intel processor as this feature in Intel processors, Speed Step, is hardware, not driver based but anyways I hope this info helps.