The View menu also provides a Display Quality submenu. Use View to change display style and quality while working on a structure. Options on the submenu are explained in subsection 3.7 - User preferences dialog . High With the High quality display style, movement may be jerky for molecules with more than a few atoms.
Surfaces are very smooth.
Lighting is most realistic. Use high quality when you want the best hard copy, or when you want to look at a static picture. Medium With the Medium quality display style, movement is done in real time for molecules with up to 200 atoms. Surfaces are smoother. Lighting is more realistic.