I really find hard to believe that your CPU cant move smoothly raceroom. There is not such a big difference between yours and the latest. Even less (usually) in gaming.
I was running a 2600K less than 1 year ago and had no problems at all. And thats a cpu from 2011.
Ross point is also very true, although it never happened to me in this game. But it did sometimes, a single texture could crash the entire game if your hardware/drivers don't like it.
Make sure your the cpu integrated graphics are not interfering or selected, check physx etc or even better, unistall the intel driver for testing. I still believe it can be a bad config or something wrong in your end.
But yeah, is really weird. If i come up with something I will let you know, but I'm out of ideas right now. Just test and check as much as you can.
PS. Just to make sure you know this, if using nvidia profiler to override AA settings, just remember that, unless it changed, you dont want to deactivate ingame AA, but keep it at the lowest setting. I think is 2xAA. Otherwise wont work.