My GPU (Sapphire 270X) has begun to enter 3D mode and raise it's clock speed while performing 2D tasks like watching a flash video or maximizing an explorer window. Just dragging the mouse cursor on the desktop is enough to get it to raise it's clock from 450MHz to 1150MHz. Once it hits about 15% load at 450MHz it overclocks to 1150Mhz. It also makes the audio stutter when scrolling on a page, for example if I'm watching Youtube and scroll down to read the comments, it will stutter and skip.
So far I have tried disabling Aero, disabling hardware acceleration, restoring stock clocks and reinstalling my drivers. None of it has affected the behavior. Clock speeds and voltage are stable in stress tests indicating the card is in good health.
I've not made any software changes or added any new hardware recently.
Edit: With hardware acceleration enabled in Chrome the clock speed locks at 1120MHz and 1.157V.
I have no explanation for this.
Edited by averysadman, 05 August 2014 - 05:49 PM.