Game's and their FPS cap.

[FearInduced]

How come Doom runs at 60 FPS on 1080p (Ultra settings). But Modded Skyrim with something as simple as RealVision ENB run at an average of 40 FPS on my GTX 970? .

Please explain this whole FPS cap thing that I don't know 100% about.

 

[hang-the-9]

Because they are two different game engines with different requirements and optimizations. FPS cap does not have anything to do with what your are asking, that is there to keep games from stuttering or lagging due to issues with how they run on specific monitor refresh rates.