Computer randomly restarting

[Tikizack]

I put in a new GPU about 3 days ago and I am having random restarts all the time while playing games. Here are my parts.

GPU- MSI GTX 960
CPU- AMD FX-4300 Vishera
MainBoard- 760GM-P34(FX) (MS-7641)
PSU- 500w
RAM- 8GB of DDR3

 

[Zerk2012]

Usually the power supply