Thanks Deadthrey for trying to help.
I dont know how to be more specific. The test scene above is an empty project with just one actor that spawns multiple static mesh components. The data shown in the screenshots are from the time every static mesh component has already been placed. So its a static scene.
In the real project I use RuntimeMeshComponent to build stuff at Runtime, but the result with the HardwareUsage is the same. So I showed off the simple scene with nothing in, as of the rule “if it doesn´t work, try a minimal example”.
I as well tried a minimal example as of above with RuntimeMeshComponent Boxes, that result in the same result.
The actual project is not much more, just more code to create the Objects placed in the world. After creation its just a mesh in the scene, no GameThread usage, just RenderThread/GPU. No changes made to Postprocessing. Im aware of the doubled rendertime for HeadMountedDisplays (HTC Vive). The needed 90Frames increases the render load as well.