Well I got told to disable hyper-threading as this sim does not like false "cores". Disable it and tell us how you get on, it worked better for me.

Worked an absolute treat! Before I was getting stuttering and 35 - 60 FPS, but now I get 55 -60 FPS and far less stuttering. I also disabled CPU TM Support because I just been reading something on an overclock site. I am also using Gamebooster.This Hyperthreading should be a sticky because it works.

Brilliant, now you can enjoy. :)

FPS solution that's worked for me.
 

I was getting really quite frustrated with this game because I have a good specs computer, but tonight with the help of some good Samaritans on here, I have finally fixed my FPS issues. The solution for me was to turn off Hyper-threading in the Bios and I disabled turbo boost. I also run Gamebooster that stop background programs you don't want running. Before I did this I was getting bad stuttering and my frames were a constant 30 - 60 FPS up and down. Now with the new setting I get 55 -60 FPS most of the time and far less stuttering. My system spec is listed below, I hope this helps someone else because I'm pleased that some people helped me out with this.

Quadcore i7 930, overclocked 4.0ghz
4gig ram
Geforce 680GTX
Raptor HD
Gigabyte X58A

I certainly can.. Thanks to all for the help!! Will this work with all games where I will have a boost now?

Hyperthreading? Turboboost where do I find these to disable them? HELP! Getting 8-20 FPS and its driving me mad...Game Booster didn't help...

In one of the older versions i tried that. It didn't work for me. But here's the question. Why disable HT when they said they just improved it it in this beta?

HT must be disabled on i7 for any type of game

I never turned it off and never had any issues with FPS. Usually averaged 50FPS + online and off with HT/boost on.
But hey whatever works!
EDIT: i7 2600K @ 4.0ghz/GTX580 1.5gb/8 gigs ram, etc...

Hyperthreading is not quite the same as multithreading (which is what hey mentioned, I believe), but if this works it's good news for the Intel crowd.