I would post this as a private message but then I thought no. As there are others out there with the same issues.
Cho's computer is a pretty high end spec and also has a brilliant mouse.
But if I remember a while back Cho you had an issue with graphics on your computer and you auto re installed driver. By deleting and rebooting. When you do this the driver is re installed from the recovery side of your hard drive. Not the latest driver.
So I said last night it could be openal as you have a 64bit system. Also I said you could so the same as me and the 32 bit version.
Well after consideration I have began to wonder.. Your computer must be clean inside as its new. Also the chip cannot be overclocked as you have not touched it.
If you overclock sometimes this causes overheat and the chip will throttle back to protect itself.
So this is my solution atm.
Go to this site and let microsoft select an updated driver for your graphics card.
Also there is another possibility have you done a malware check lately. There are some serious spybots around atm and they tend to piggy back of your system and plunder some of your resources. So just for the record. Check out that nothing else is running in background.