In agreement with the other responders that your system isn't really up to current simulator and gaming requirements - and, this IS a beta (I made my purchase already).
However, having written that, I'll agree that there's much work to be done particularly regarding the full use of computer resources - there seems to be no definitive correlation between XP v11b2 settings and CPU/GPU usage.
Here I have perhaps a higher end system (Asus Rampage V 10, i7-6850K, 32Gb DDR4 ram, all SSD's, dual GTX-1080's, etc. Even with this, the best FPS (single GPU with Anti-Aliasing OFF) I'll see is 24-27. If I force the system into SLI, I'll see an increase of 5-7 FPS, into the low 30's or so. Even with this, the GPU & CPU are still "coasting" in terms of per cent utilization.
Again it's in beta; here's hoping this is all sorted out and I'll soon be seeing 50-60 FPS. Cheers.