Framerate drops after period of time.

[Gamerkought]

Hello, Amnesia seems to run fine at first until after awhile, anywhere from 5 minutes to an hour or more, the game suddenly drops dramatically in framerate, from the constant 60 to 20-30, at which point I have to restart the game.

My drivers are all updated, and I disabled Aero. No other processes are running in the background, although perhaps the steam overlay is causing it...

Nonetheless, it almost seems like a memory leak, but I am not sure.

Thanks!