[zanzark]

I'm playing COD right now, at an unconfortable 22-30fps.

My GPU is a 6950@920MHz 2GB, BUT the game is using only 66% of the GPU capability. (As reported by GPU-Z and AtiTrayTools)
I had a 6850 1GB before and I had no FPS improvement when I got the new card.

My CPU is a Phenom 1090T X6, but the game uses only 1.5 core at most.

So I assumed the Sim is lagging at the CPU, as it's uncapable of using more than 1.5 core.

I put the plane in autopilot over the sea and logged the FPS:
CPU@3200MHz = 29FPS
CPU@3700MHz(+15%) = 33FPS (+14%)
CPU@4100MHz(+28%) = 37FPS (+27%)

So, the big problem is the CPU and the fact that the main thread runs on only 1 core.
If they could mutithread it, everybody using 2+ core CPU would have a massive FPS improvement.