Speed up the display of AutoCAD 3D solid models - Solution

A drawing that contains 3D solids responds very slow when navigating (panning, zooming, and 3D orbiting) or when executing commands.

Causes:

A drawing that contains thousands, sometimes hundreds of thousands, of individual 3D solid objects can dramatically slow performance.   
The large number of objects can be the result of imported data that are fragmented into separate faces or other graphic elements.

Solution:

Instead of recombining the objects, reduce the display processing to lessen the effects. 

The following changes can improve display time:

• Set the visual style to 2D Wireframe or Shaded when panning, zooming, or using 3DORBIT. To display the intersection edges of combined 3D solids, use the –SHADEMODE command and specify the Gouraud + edges option.
• Turn off the intersection edges in any visual style that you plan to use (Show = No).

• Turn OFF the display of silhouette edges (DISPSILH system variable).
• Turn OF the ViewCube display (NAVVCUBEDISPLAY system variable).
• Turn OFF perspective display (PERSPECTIVE  system variable).
• Turn ON adaptive degradation (–GRAPHICSCONFIG system variable).
• Turn OFF adaptive degradation (-3DCONFIG system variable).
• Unload some or all Xrefs.
• Use Xref in place of blocks.
• Use the Partial Open option of the OPEN command to limit the number of objects displayed within a drawing.
• PURGE the drawing.
• -PURGE REGAPPS.
• Remove solid history via the BREP command.
• Type REGEN 3 to regenerate the solids again.
• Turn off Smooth line display under 3D Config.