Hello, I ran into this SAME issue. The fix was the dynamic shadow mod. http://www.nexusmods.com/fallout4/mods/1822 I have: Intel i7-4770k @ 4.4 Ghz SLI GTX 960 4GB (Both cards OC'ed) Back in december I was getting 60 fps solid. Then after running it again recently, I would get 45 ~ 50 fps in the wilderness, 10 ~ 25 in the city areas if I was lucky. Someone pointed me to dynamic shadow, now im back with all my settings on very high (cept' godrays) :D Getting a solid 60 FPS now, occasionally it will drop to 50 if there is a crap ton of stuff to render, but it pops right back up after a few seconds.