Titanic14, I have a couple of suggestions for you. I run a very simular setup to yours. I think the biggest problem is your CPU. We are both at least 1-2 generations behind the I-7 proc. So you need to make trade-offs. look at the Anti-Aliasing and Anisotropic settings on your video card. Dial them down a bit and you will see an increase in frame rate. VSTEP has added sooo much to this version of SS that there is just a LOT of graphics overhead. I run a bunch of Sims, Flight Sim X, MS Train Sim, SSE, rfactor racing. They all have to be adjusted because of their eye candy.
My setup:
Dell XPS 720 H2C, Intel QX6700 3.8Ghz, 4 GB RAM, 2 Nvidia 8800GTX OC's in SLI running 3 Samsung 24" Monitors by way of a Matrox Triple-Head-to-Go Digital version, 6TB of Hard Drives.