So basically I did everything what I found here, but still I've got some freezes. It doesn't matter if it's online or offline. My green and purple bar looks all the time like that. Anyway - this purple bar during the freeze is maxed out (but I don't know how it's possible from only ~15% to max in one second :/)
My green bar looked like this from the first time I used rF2. I've always had issues with micro stutters, even when no visible frame drop from 60fps (vsync, single 27" monitor)
A few weeks ago I noticed that when I'd load up the GPU like the poster above advised, it did help. Once a server was loaded with people and we were racing, all smooth as butter. Alone and on a track that isn't resource heavy, I'd again get the issue.
I finally broke down and tried Rivatuner (to lock at 60) because the other night I noticed that I was getting a very small framedrop (59.9fps) then it would jump to 61, then back to 60. I realized this coincided with the microstutters.
I got rid of my in game (plr.json) frame limit and allowed Rivatuner to do that work.
Instant, HUGE difference! Green bar now full, but no little spikes in it at all. CPU usage decreased.
Framerate stays a cozy 60fps and not a single micro stutter in sight, even at tracks and with cars that I used to have a ton of trouble with.
This is not the "logging out of realtime physics" issue that this thread focuses on....but, if one is having this microstutter issue I'd highly recommend giving Rivatuner a shot.
Also,
credit to the author of this thread for pointing this out.....it'd been on my radar for some time, just hadn't had the motivation to move forward with testing it. Now, wishing I'd done so long ago. The countless hours wasted trying to solve an issue that was so easily remedied...