I'm getting poor performance too, in the training missions between 26 - 35. My specs:
i7 3930K @ 3.2
32 GB Ram
GTX 680 2GB
I don't get this low in other aircraft, and I understand that there's a lot going on in the MIG21 simulation but I thought I would get better. Maybe once EDGE is out it will be better optimized?
Edit: Running the latest 340.52 Nvidia drivers.
Edit2: I'm running the sim @ 1920x1080, everything on high with 2xAA except for view distance, HDR set to off, clutter/bushes set to 0, tree distance set to 6000