as mentiopned, the location is important…
You can check fps at EDDF versus FLHN. And these 30% looks just like the cpu-limit. We should of course also aware, that LOD is not the only option. There are other airplanes, ground personal/cars ( ground desity settings), etc… all comes into the render pipe…
Most users eyes needs at least >25fps as minimum…
Example
3840x1600 , i7-8700k, 2080Ti ( LOD = Terrain lod , others at ultra , dx11 , disabled vsync for the tests )
EDDF, Parking 604 , Twin Otter ( cold ) , sunny day
- LOD: 400 → 17fps ( gpu 40% )
- LOD: 200 → 26fps ( gpu 60% )
FLHN, Parking 14 , Twin Otter ( cold ) , sunny day
- LOD: 400 → 47fps ( gpu 100% )
- LOD: 200 → 48fps ( gpu 100% ) ( just gpu limited now )
quick compare with Full-HD to check the cpu limit theory
1920x1080 native setting
EDDF, Parking 604 , Twin Otter ( cold ) , sunny day
- LOD: 400 → 19fps ( just same , gpu 37% )
2303x959 with renderscaling setting 60 ( want to come near same amount of pixels ) - LOD: 400 → 17fps ( just same , gpu 39% )
By the way , DX12-Beta makes no difference…
And more foucesd to the topic itself, you will also not see any difference with the NDU registry hack.
Screenshots with taskmanager core view I can add if necessary.