Problem with my Brand new Build? maybe my GPU i dont know

terminator123

Honorable
Sep 16, 2014
830
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10,990
Hi,
I have built a new computer recently and it's been running brilliantly until I installed my old graphics card into my new computer. My graphics card is a GTX 660 and before I was using on-board graphics.

When I play Arma 3 or Garry's mod or maybe other games (I'm not sure) sometimes it happens after about 5 minutes of playing, sometimes 1 hour or more. My game suddenly starts to go really slow and the sound deteriorates, then my PC freezes because of this problem when Arma 3 or gmod is running, and my internet just disconnects. I then HAVE TO restart my whole computer

I don't understand why this only started happening once I've installed my GTX 660.
It only happens when I play games (at the moment them 2 in particular)

I was wondering if somebody can help me out as I'm quite concerned.

I have an intel i7 4970k
850 wat evga psu
2400 mhz ram g skill 16gb
gtx 660 etc.
 

terminator123

Honorable
Sep 16, 2014
830
0
10,990


ok im doing chkdsk
and okay um my gpu at idle is around 30-50 degrees. when playing arma 3 70-83, when playing smaller games 40-55.
my standard hdds are 27 and 31 degrees