Thank you for your reply.
First thing I tried after reading those threads was to entirely remove Thread.Sleep() from Game.Tick() Function.
To eliminate any form of inaccuracy while sleeping. Of course this results in a 100% cpu load on one core. But sadly the issue persists.
I figured out that once the stuttering starts EndDraw() --> Platform.Present() suddenly takes up to 30ms to execute.
Before that it normaly takes 0ms to run.
recordet times:
0
17
29
0
29
1
29
0
29
29
0
and so on
Next I will try to look into Platform.Present()
Finally leads me to SwapChain.Present()
which means I need to continue diggin in SharpDX or give in…