So I finally got round to trying out this amazing game, installed it correctly on a vanilla game and all. But I'm having a serious issue with sudden drops in framerate, I'm not talking from 60 fps down to 50 but down to 10 or lower. It seems to occur randomly or in well lit areas where there's flickering candle light and fire but other times it happens in random outside areas, maybe when I'm near a camp fire?
I don't have lighting or fire mods installed, I've tried lowering my settings, no change. I've installed the optimised textures mod, no change. I've turned off V-Sync, One Tweak, lowered the shadow map resolution in the ini files and it still happens.
For an example, just now I started up my game from a save where I entered the Undercity inn, as I was at the door the game was smooth and at 60fps but as I went down the stairs and started talking to an NPC the framerate dropped down to 10.
Any clues?