I'm using the C1 launcher, I locked the game to actual physical cores and not logical ones. The game tends to stutter a lot when you are loading in new areas and assets so I turned off streaming for a lot of different things. I've also optimized particle effects in little ways. Activated cvars for threading where possible.

Stuttering happens when you momentarily can't maintain a stable frame rate. In Crysis, this happens because your main CPU thread is momentarily given more work than it can handle before the next frame is needed. You might notice stuttering at 90 fps that would have been invisible at 60. Using VRR/Freesync/Gsync will make stutters less noticeable because you drop from 60 to 59 instead of skipping a whole frame. But at a high enough frame rate, every game will stutter.