Game stuttering and FPS drop after an hour or so of playing..

[Ravenbear]

After about an hour or so of plying I get massive FPS drop and stuttering, I have run stress tests and neither my CPU or GPU are over heating and throttling down. I drop from a steady 100fps to the 30's or lower and it does not matter where I am.

This is my system http://www.3dmark.com/3dm11/11248535 and there is no way even at ultra graphics I should have this happening, and I do not have it set on ultra. I have shadow boost running as well as the newest ENBBoost..

Can someone help me figure this out, i have spent hours trying tons of different things and nothing seems to solve it.

 

It's got to be a mod or setting but for the life of me i can not figure out what..

Thanks for taking the time to read this..