That CPU-Z screenshot in your first post indicates your GPU is at 850 MHz, but it also indicates that is the speed on GPU 1 which is your Intel on-board graphics. Can you confirm your core speed on your GTX 590? Default is 613 MHz.
607Mhz is my core speed, out of the box.
The thing is that I played higher end games, from BF3 to Crysis 3 and it never went 92*C.