Most probably your PC is dusty. You should clean up the dusts in the fan of your desktop. I used tohave the same problem, but that was after a few minutes of gaming.. Lol. Once i cleaned the fans then no problem till this day.. But just to make sure, try cleaning it first, unless youre using a water cooler. The other option is to check the temps of your cpu and gpu. I dont think your psu would be causing the problem. Corsair PSUs are in good rating. im using a corsair one too. No problem whatsoever. haha.

Your PSU should be more than enough to support.. Lol. 970 is about 90W your i7 also maybe at most 125W. lol.

Well, in my case, dust build up in the stock heatsink fans and cause heat ups when i play any games. After about 20mins or so my PC shuts down. Then i cleaned the fans no problem whatsoever after that. It could be due to the dust stuck at the PCBs of my boards... lol

Haha. Well thanks for the clarification. But I was just assuming that its around that range, since from 900 series onwards they are reducing the power consumption of GPUs.. xD

Oohh. Right.. Lol.