Xplane 11 Low FPS

[lovis]

Hey guys after a year i got back to Flyinside and Oculus Rift .
With the new Xplane 11 and the ixeg 737 i fell in love with the idea of VR again.
There is just one problem . The game hast around 40 FPS without flyinside with it i get 30 in the Xplane cessna and 16FPS in the IXEG .
It is nearly unplayable , i attached my Xplane 11 Settings they are allready very low .
I allready did a clean reinstall of Xplane , even my Flyinside Settings are not that high .
I know i dont have the best PC Specs but with P3D it works nearly perfect.
Are there any setting better for my System or any tweaks with xplane 11

And one more question , is it normal that if you move your head there are these black Window corners .

System Specs:
Intel Core I7-6700K 4GHZ
16GB Ram
Xplane 11 Installed on the SSD
AMD Readon R390

https://ibb.co/mtW2SQ