I had a file recently from a user with a similar problem.
It turns out for him, that the file had originally been brought in through Revit. It had tens of thousands of independent mesh facets that should have been Joined into a few meshes. Rhino won’t let you Explode meshes into individual facets for this reason but we can’t block bad geometry when importing it. Once the mesh facets were Joined, the performance problem went away. It has nothing to do with your graphics card.
This sounds quite promising and yes it is imported model, however much of geometry was turned into polysurfaces, and also the remaining meshes contain low number of polygons.
It seems to work very fast in wireframe, only turning the view into shaded this problem emerges.
Sure. If it’s not too big, attach it here.
If it’s large, use the tool on the Support page to upload the file to support.
Fully describe the problem if you use the upload tool so the support tech that receives it will know why you sent it.