thanks for sharing…
Important are these views of Taskmanager:
Then you might see an image like this in which one Core is at 100% and these is the limiting factor:
( topic )
( edit: I forgot to clarify… if you see one core in 100% and your gpu is not in 100% , then your LOD is currently to high for your single-core-cpu-power. In the linked picture you see a optimal situation with a tuned LOD setting for my CPU ( 220 ) ) )
Why in your case the language have an effect, still not sure.