We recently received a users drawing and found it to be redrawing and regenerating *extremely* slowly. After a while we discovered that the VIEWRES was set to 20000 !!! While there may be instances where you need to bump it up a little, don’t use a higher number than necessary.
Issue the VIEWRES command and answer Yes to the fast zooms, then enter the smallest number that gives smooth circles at most zoom levels. If you zoom in tight and circles don’t look round simply issue the REGEN command. You should be able to use 200 to 500 with good results. This value is stored in the drawing.