It seems that when CPU usage hits 100% the inputs from kb and mouse don't fail gracefully, at least with BF3. This has only been happening to be with a new mouse (logitech g9x) and only 'lately' with just battlefield 3, I've tried everything like lowing the polling rate of the new mouse to 125 (lowest you can go... it's very low), setting the game back down to everything low/off including resolution, and while all of those things help cpu usage for some reason I still get just as bad mouse/keyboard latency. What the latency feels like is like my inputs are on ice, they 'slip' when I use them like a tire on ice when it spins too fast. For one reason or another I could run the game at High before with zero issues, silky smooth inputs and while my framerate wasn't exactly 60 all the way it was playable almost all the time.
What fucking causes this, what can I fucking do about this, the internet has almost zero answers that I can find with google and this makes me very upset. Issues with my PC that 'just happen' always upset me because they are rare and usually end up un-treatable.