Almost all (if not all) graphics cards use single precision. OpenGL apis have functions for double precision, but I haven’t seen a card yet that really uses those numbers as doubles. When Rhino geometry is far from the origin, we place a scaled and translated copy of the geometry on the GPU with values that are “nice” for floats. We then apply the transform to the world to clip matrix in double precision on the CPU before setting the world to clip transform in a shader.
There is a difference between visual inaccuracies and numerical inaccuracies for geometric calculations. We should have most of the visual inaccuracies fixed at this point. If there are samples where things look wrong in Rhino 7, please let me know.