I don't know if this is bug, I have fps problem. Game fps always around 30. It wasn't like this before. Now I have 40 ~ 45 fps at menu and 30 fps in game. I tried so many things that people suggest, like nvidia control panel > trilinear buffering: on, max performance settings, without mods, without caves... always result is same. Even tried to play windowed, got 60 fps but as I play it dropped 30 ~ 40 again. Anyone have that issue ? Please help me. This issue really makes the game unplayable.
pc specs: i7-4710MQ CPU @ 2.50GHz
GTX 860M 2GB