I've been playing Crysis 2 and Skyrim on my Retina MacBookPro (10,1) for months now. The two games used to run super smoothly even on nearly maxed out settings. This laptop has an Nvidia GeForce GT 650M graphics card inside, it runs great.

But I recently replaced my Windows 8 consumer preview with the retail copy, and since then, 3D games lag in this odd way, no matter what the graphics settings. Every second Skyrim and Crysis alternates between running smoothly and lagging. It's a cyclical lag that comes and goes like clockwork. I can turn the graphics down to 800x600 with no antialiasing and low texture quality, and it runs much smoother on the "up" motion of the cycle, but every second it moves back into this lag spike.

I've tried installing beta graphics drivers, re installing the operating system, re installing the bootcamp support software, and freeing up space (I have about 20 GB free). I can't figure out what suddenly caused this other than some obscure difference between the consumer preview and the retail version.

What can I try? Is my video card failing? Are there some other drivers I can install? This isn't normal lag from maxing out the card, it