Setting shadows in densely populated planets to Uber lowers framerates to 10fps and lowers my gpu usage at the same time. However, if setting it to High my fps goes to 70fps and gpu usage is normal again. Cpu: I5-4670k at 4.5ghz Videocard: Geforce 560 Ti 334.89 driver 8gb ram.
shadows are probably calculated on the cpu and if you set them to uber the cpu starts to slow down which in turn slows down the gpu since it needs the data from the cpu to render the scene. just an educated guess, i actually have no idea what the problem is.