REVIT MEP 2010 Plumbing/Fire Protection Model is SLOW. Try to change a pipe size and you will see what I mean. The file size is not big at all (25 MB) this is not normal. I am using a 64 bit 16GB Ram machine. I tried disconnecting some of the systems and still seem to be slow as christmas. User is not sure what the last thing that happened before the model began reacting like this.