gigabyte hd 7850 1gb oc problem

SH K

Honorable
Jan 16, 2014
2
0
10,510
So i built a new computer (for the first time) and i used following builds
cpu: AMD Fx-6300
graphics card: gigabyte radeon HD 7850 1gb oc
MB: ASrock 970 Extreme4
PSU: 500w

well when i play some intensive games like Crysis 3 or Battlefield 4 after few seconds or minutes of playing the game the screen goes black or makes a dark coloured stripson the screen, but when i play LOL and AC3 its fine
and i also can't finish the window system rating about 1 quater of the way it happens.
Do i need to refund this graphic card?
(i also have updated gpu bios and driver)