It might mean that the complexity of the mesh (or another object) has created to many nodes/polygons for the amount of RAM that you have and AC is hitting the maximum of your system when either opening the 3D window or refreshing a section or elevation.
Solution (besides adding more RAM) is to simplify the mesh, turn it off or do the calculation in another file that only has the mesh.
BTW 40Gb of hard disk space has nothing to do with RAM which you either have 2Gb - 4 or up to a max of 32 in current regular Operating systems.
Eduardo Rolón AIA NCARB
AC27 US/INT -> AC08Macbook Pro M1 Max 64GB ram, OS X 10.XX latest
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