Fps: 20-70

I have tried everything to boost my fps but nothing has worked.. Problem started recently i had good fps before.

Specs:

GPU: Corsair HX 850W PSU

CPU: AMD FM2 Athlon X4 760k Black Edition With Cooler Master Evo 212

VGA: Nvidia GeForce GTX 670k

Ram: 8GB

OS: W7 64-bit