If you have tested both drivers, our drivers and the manufacturer's drivers then as a last troubleshooting step you may considering a BIOS update to your motherboard, if this does not work then the processor's graphics controller may be defective and therefore you may considering a warranty replacement with the place of purchase.
I am experiencing the same problem with an intel i5-2500k and Gigabyte z68X-ud3h-b3 motherboard. This is the third motherboard that has experienced this problem(unrelated issue) and through that and other tests I know that it is the onboard CPU graphics causing the problem. It works for an indefinite amount of time, then without warning(though video playback seems to cause it) the entire screen is filled with flickering rows/boxes of artifacts, the speakers blare a constant glitchy-sound and the entire computer freezes up until I hard power cycle it. At that point, it boots up fine, anything that was open is usually recovered, and all is well until it happens again. I have tried all drivers available to me, mobo BIOS versions, tweaked settings, etc. and it seems that any intel driver greatly increases frequency of the problem. That is the only real variable that has a significant effect, but it still occurs without them installed. Does this sound like a defective CPU graphics controller?
If so, assuming it is covered by the warranty, how would I go about getting it replaced?