Crashes while playing games

George Scott

TS Rookie
My computer crashes whenever I play games on it. this happens after a few minutes of playing or as soon as it loads up on others.
I used to have nvidia 660 ti but this had same fault so I got a replacement and this still does the same thing
Cpu: intel core i7 3770k oc to 4800
MoBo: asus P8Z77-V LX Z77
GPU: amd 7970
Ram 32Gb corsair vengeance
power supply xfx 750w modular
OS: windows 8 pro 64 bit

I believe that my computer is over spec so why does it crash??
 

Tmagic650

TS Ambassador
In the CPU frequency bios settings, disable C3/C6 stepping and any CPU throttling or speed control. This should stabilize the game play