random pc shut down than playing some games

[Dre3amwaver]

hi everyone I first off would be very greatfull if someone could tell me how to solve this issue that's been going on for a few weeks now. I have just purchased the msi r9 380 and I already have a 800w psu but when I play ARK survival evolved if works for 2min approx. then shuts off completely as thos I have just pulled the plug no warning nothing. then it takes a about 10min to want to start again why? my temps of my cpu and gpu are running around the 73degrees c mark all help is needed thanks...

 

[mlga91]

Post your entire specs, including the brand and model of your PSU.