gpu usage is usually 30% or lower, when I pause the game with J the usage gets higher 60% and the fps is improved. If I unpase on modded maps the usage is the same but on other maps it gets back to previos. most cpu usage I've got was 62% with 5 cars crashing. And the I spawn the gabester h the fps is LOCKED at 24. I hope this gets fixed in the future because I should be getting much much higher framerate. FX 8320 GTX 760 4 GB 1600 RAM
I'd try a couple of things, one if you haven't already overclock, also unpark your cores. (I assume you have a 64 bit os) The only bottleneck i could see is that you only have 4gigs of ram. I have a 8120 oc to 4.2gh with 32gigs of ram and a 6870 and it runs the game just fine ~60 fps all the time.
What are you doing bumping someone else's 7-month-old thread to ask a question? Try using a wonderful search engine called Google.