Started few days ago. Playing world of tanks after starting a match the screen would freakout and a wack load of weird shapes and colors started to flash around and either system would reboot or I would have to reboot.  It was only in that game... Starting today its done it in Warframe also. And valley bench also frames dropped super low and I had to reboot computer also ... 
 
So I upgraded drivers clean installed them. Did not change a thing still does it. 
 
I then loaded cpuid HWmonitor 1.32 and its showing fans even at idle 0% pwm and rpm 0
 
could not get a reading when last ran  valley bench so tried in windowed mode same issue and fan speed and power never changed from 0
 
I ran these games and benched it and was getting 60 - 80 fps at 1080 with everything cranked to the max... Now it sucks  I am regretting buying EVGA