Ok now I’m positive that this is a Rhino problem. I spoke with a chat supporter from Nvidia that checked the GPU-log and couldn’t find anything wrong with the card. I had to install a very handy utility called GPU-Z which has a lot of information about the GPU besides the temperature.
I compared Rhino to Blender and from what I could see Rhino is handling the GPU as if Rhino needed full ressources from it all the time.
In the moment I open Rhino the clock and memory allocation goes from 210 Mhz and 101 Mhz to 1000 and 1600 where it stays.
In Blender when ever using the Viewport to orbit or model or change something the clock speed rises a bit depending on what you are doing but in the moment you release the mouse and stop viewing and changing things the clock speed goes back to 210 Mhz and 101 Mhz as you would expect since the GPU should ony be called and ressources allocated when there’s need for it.
Im positive that this must be a Rhino bug.