Rhino 6 Performances Issues

Yes I know, I used to work offline.
But now I am going to drop that laptop and continue working on the new PC, which is weirdly performing in the same way.

Ok, so you are saying that this is not an enormous file and I should be able to work smoothly on it. What I do, but only in shaded viewport. If I switch to rendered it slows down a lot. And if I give a look to the task manager, it tells me it is only using a small percentage of CPU and GPU while chopping in rhino.

The selection looks fine.

I am afraid this is only for Rhino 5. When I install it on the laptop with Rhino 6 it tells me this version is only built to run on Rhino 5. Something similar happens with the PC with Rhino 7.

Smoothly in rendered viewport, with materials, groundplane on ecc.?