I'm having issues with a computer I built about 8 years ago. It randomly freezes and/or crashes. Sometimes it freezes but then unfreezes after 20-60 seconds or so. I ran all the OCCT tests and the only one that had problems was 3D Standard. About 75% of the time, it would freeze or crash, usually within a few minutes of starting. So, my first thought is to replace my GPU, an NVidia GTX 960. My question is this: what are the chances it's something other than the GPU? Motherboard is Gigabyte GA-970A-UD3 and processor is AMD FX-8370E.