Just want to chime in to say that this is ruining my experience of the game, I get stutters every 10 seconds that drops the fps down all from 10-20 fps every stutter. Graphics card: GTX 1070 Ti. I've tried the Special K-mod which gave me some frames (the setting that halves the number CPU cores used helped me and many others) but it didn't solve the _consistent_ stutter issues. Obsidian should look into what the mod is doing + maybe get on with getting the external support.. we're 1+ year in with these issues.
