Okay this might be old news to some of you but I figure it might help some poor soul out there with a slow computer
If you are done with the geography for your map but are still working on the statics, put your map0.mul aside and then make a backup of your scripts folder (the one in the dragon directory). Then, open up the scripts directory and delete all the folders except 'items.' Then open up all the text documents and remove all the contents except for groups.txt and items.txt. Now open up items.txt and specify only the statics you currently want to test. This helps a lot if you are trying to perfect the number of stalagmites in the caves, or the number of brambles in the forests, etc. Just don't misplace your backup!
Now compiling takes under a minute
I hope this helps people.
-Derek