Two quick things I can think of.
1. Are you viewing the 3D image with the OpenGL engine or the Internal engine? (Internal engine can be extremely slow with large models regardless of the video card).
2. Do you have the latest drivers installed?
Barry.
One of the forum moderators.
Versions 6.5 to 27
Dell XPS- i7-6700 @ 3.4Ghz, 16GB ram, GeForce GTX 960 (2GB), Windows 10
Lenovo Thinkpad - i7-1270P 2.20 GHz, 32GB RAM, Nvidia T550, Windows 11