Facing this bizarre issue with this game, runs absolutely fine at locked 1080p60fps on max settings on my laptop (Yes, I have it set to run on my dedicated NVIDIA GPU). But for some strange reason, after EXACTLY 5-15 minutes of play the framerate will drop to almost half and run even worse when menus are opened. The only way to fix this is to restart the game, only for it to happen again after 5-10 minutes.
Tried all the solutions on the web, including installing the latest Special K's ".hack//G.P.U." fix.
Probably hopeless posting here, but it's much better than Steam forums where people will link to the obvious.
To repeat: I am indeed running it on my dedicated NVIDIA GPU, and the game runs totally fine until after a set amount of time (temporarily fixed by restarting the game, repeat). Almost as if there's a weird memory leak situation. idk.