So this has worked for me and many others, it might work for you too so give it a try.

The problems: Game freezing/crashing, stuttering, and overall poor performance and input lag.

Possible cause: I still am not sure why this is happening, but I think there is an issue with CPU bottlenecking. I was getting 100% CPU use with only about 15% GPU usage. I think in the long run 343 needs to address this

The Fix: Cap your FPS at some level BELOW what you are normally achieving as your max. For example, if you are normally getting 100 FPS in arena, try to set the cap to 90 (enter a custom limit). This seems to take a huge load off of the CPU and fixes much of the stuttering and crashing, also just makes the game feel smoother. I have seen people already suggesting capping the FPS at 60, but it doesn't necessarily have to be 60, just anywhere below your average FPS (this can vary between arena and BTB. I also don't think the minimum FPS affects much, but feel free to test this.

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I hope this gains visibility as it will help many people on PC.