Freezing in game


Aug 31, 2012
I've been having an issue when playing World of Warcraft. It seems to be specifically tuned to that game so far, although I'd assume that with something like this it'll just get worse and worse. I built this pc around a month ago and had absolutely no issues. Recently, however, I began to get freezing in the middle of a game. It didn't matter if it was just standing still with zero strain on the machine, or with high strain. It just happens randomly. I can't recover at all from the freeze, and there is a low buzz sound coming from the speakers. I'm now also only getting 30-50 FPS in certain situations/places where before I was getting 70-100. Another issue was my video card will not work in my middle PCI-E slot but works just fine on the far one. I've tried a different card on the middle slot and it works just fine.

My machine is as follows:

Intel Core i7-3820 quad core 3.6Ghz
G.SKILL Ripjaws Z Series 16 GB DDR3 1866
Corsair CX Series CX750 (750W)
XFX Double D HD Radeon 7950 3GB DDR5
EVGA X79 SLI Motherboard
Intel 330 Series Maple Crest 120gb SSD

Things I've tried thus far:

-Several 10 pass memory diagnostic tests.
-Furmark stress test for 5 hours with no issues
-Prime95 stress test for 5 hours with no issues
-Uninstalled/reinstalled drivers
-Flash updated BIOS
-Updated firmware on SSD
-Made sure all cords were sufficiently plugged in at all times

I assume it's either the MOBO or the video card. I just wanted to get a few other opinions since it's really odd that the card works in one of the slots and not another. I originally thought it was the MOBO until testing the second card with no issues. Any help would be appreciated.