Regardless of how I configure Vsync in the game, after a few minutes of play, the framerate is capped at 30 fps. I must restart the game to get framerates to return to normal.

Vsync on: framerate begins at 60 fps, then after a few minutes of play is capped at 30 fps until I restart the game.

Vsync off: framerate begins at ~300 fps, then after a few minutes of play is capped at 30 fps until I restart the game.

How can I remove this 30 fps cap? I have tried to force vsync through the Nvidia control panel, and it does not help. When the cap is a 30 fps, video is noticeably "jerky".

System:

Core i5
Nvidia GTX960 SSC
Windows 7

Anyone?

This is a known issue on operating systems after Win XP 32-bit. It's been discussed here:

https://www.gog.com/forum/fear_series/low_performance_fix/page1

It has to do with HID-compliant devices. They need to be disabled to get Fear to run at peak performance.

This video shows how to do it:
https://www.youtube.com/watch?v=c563frrNxHQ