When I'm raising, lowering terrain with the cliffs and ramps, or the other more gentle raising and lowering (that doesn't technically change the in-game altitude) I notice that my FPS drops to literally 1 sometimes, whereas other times its updating in real time like its supposed to. This is incredibly annoying and I don't like having minor mountain ranges (a regular feature in my maps) take 20 minutes to make, one click at a time. Why i sthis happening? I've tried changing graphics settings, closing other programs, nothing works. wtfx

I don't know anything whatsoever about SCII as I can't run it, so these questions will likely be useless, but seeing as no one else has asked anything...

Does this seem to occur the most when you alter specific parts of a map (i.e. the center, a corner)?

Does this seem to occur the most when there are units or doodads at the area you're altering?

Does this seem to occur the most when you alter certain types or textures of terrain?

Does this happen a lot in some maps but not in others?

Does this seem to occur the most when certain lighting conditions are present?

No thats whats so mystifying, its totally at random it seems. It affects (for no apparent reason) some parts of the map but not others. And I'm talking about raising elevation on a totally blank slate, without doodads or lighting. It will just decide some mountains or areas deserve to be laggy and others should work as intended