new gaming computer

I purchased a PC yesterday(assembled) and when I came home, I wanted to see how it performed. It seems to be lagging in every single game. The FPS doesn't even go beyond 10 in game, however in menu it is pretty smooth. Please help me. Note: GPU usage goes to 100% in game. The power connector is...

Hi i was just wondering what PSU should I get for an I5 4670k, two gtx 980's in a corsair 350D. I have a friend that he said I should get 1000w PSU but I have ask around heard from people that 750 or 850w would be fine. So my question is 750,850, or 1000w PSU are 1000w is overkill for this...