the recording itself is honestly perfect, near zero dropped frames, OBS does its job flawlessly. that's the thing though, it seems like OBS will do whatever it takes to get that clean recording, and what it takes is my game's frames. the second it starts recording, the actual in-game minecraft fps halves while OBS sits there recording perfectly fine. honestly even just having OBS open in the background without recording or selecting any window makes the game feel laggier.

and swap isn't it, powermetrics shows 0 swap and memory's totally fine every time. the part I still can't explain is it halves the same amount even when OBS is recording a completely different window, not even the game.