I hear you about the OS needing resources, but I have never seen anything like this before. Check out my new screenshots. First one is from me starting the game up normally, no Afterburner and running around the map. It was noticeably jerky. Something just felt "off" to me.

https://i.imgur.com/VoCUGkg.png

I minimized the game, went into task manager and changed the processor affinity from 4 to 1 and then back to 4 again. Then I went back into the game. Here are the new graphs from running around the same area. The game felt much smoother to me.

https://i.imgur.com/oMd53lI.jpg

I don't get it.