So you ask, are we talking about CAD for modeling the 4th dimension? No actually I am talking about 2-dimensional materials. Well actually materials which are only 1 molecule thick, so almost 2-dimensional. Researchers at the University of Manchester have discovered a structure of carbon, called graphene, which has allowed them to create a fabric just one molecule thick. This discovery has brought us one step closer to the creation of nano-computers. By reducing the thinkness of the materials a computer device is constructed from designers can reduce the distances that electrons must travel and sigificantly speed up their processes. So don't throw out your CAD system. But maybe someday your CAD system will use a processor that has components which can only be measured in 2-dimensions.