Cool the CPU down. This isn't an Intel forum but that's a tad high. Other thoughts are the driver in use, try going back to the 20.8.3 using DDU in safe mode. Test that ADATA SU 800, I had one of those get funky and start reading real slow, wound up doing an RMA. Ok for a cheap drive in a pinch but not everyday use. Finally we get back to the CPU, man that system is old. In the end, you're trying to play a AAA title with some really mismatched hardware.