In short, I don't need to overclock my 2600k to run BF3 / overclocking my CPU isn't going to increase my performance. 2 reasons:
1) BF3 isn't a very CPU intensive game. Therefore, my CPU isn't my bottleneck.
2) I did have it overclocked to 4.0, but the response time of the CPU was very erratic according to the PerfOverlay in BF3. My CPU graph was very jagged and there was considerable micro-stuttering. When I reverted back to stock settings, it smoothed out.
Really, my question isn't a "can my PC run this" question. I know without a doubt that I have more than enough horsepower for BF3.
My question is more so: "why aren't my Crossfired 6950s eating this game alive?"
In my eyes, there is something wrong with the CFX setup, driver, etc. That's why I came here - I have tried everything that I can think of. I would think that my PC would put out much more than 35-40 FPS on those Ultra settings (minus MSAA).
Thanks for the response though.