CADD Apples vs. Revit Oranges.

I had an interesting question posed to me by my project PM the other day. He asked if a million plus sq. ft. project in CADD was as intense on computer hardware as a Revit project of the same size (keep in mind he doesn't touch Revit and we just finished an actual million plus sq.ft. project in Revit but THAT is a topic of another post). The quick answer was no, not even close, Revit is much more intense on computer hardware. But they are also VERY DIFFERENT from each other and it made me realize that this could be a question asked by a client or another design professional who is thinking about making making the switch. So I thought I would share. My detailed answer was as follows;

I said the million sq. ft. project in CADD might be the same size cumulatively as a Revit project but would be broken into smaller "pieces" in the form of individual drawings (dwgs) for example; 100 or so, 2MB-8MB dwgs vs. a half dozen 100MB-200MB central file models per discipline and/or partial building model(s). Revit, for the most part is an all inclusive database in ONE file whereas the same project in CADD would be several individual dwg files contained in a project file folder(s).

The management of the data may be more intense with CADD because there are more separate (smaller) pieces of data (dwgs, jpgs, etc) to keep track of, where Revit has fewer (larger) files. However, Revit still has an edge over the hardware performance and will bring a computer to its knees quickly. The solution here is smart modeling. One option (among many others) is breaking the model up geometrically, by scope of work or by discipline and placing model components on different worksets if the model gets too big. You could then link the models back together (again, this is a topic for another post). This allows you to control what you can open, initially and after, in the model. Otherwise, if you have a large complex model and/or a weak computer you will either be waiting a looong time for it to open and/or you will crash your computer. Going nowhere fast.

The separation of the model based on building geometry, discipline, or scope of work should ONLY be done if model performance is poor. Model performance will get slower as the size and complexity of the model increases (as it would through typical project workflow). So you might have to re-evaluate your model more than once over the duration of the project. Otherwise keep the project as one model if possible.

Hope this helps.

The shift is gaining momentum...

We choose to use Revit not because it is easy, but because it is hard. This blog is brandy spanking new and came into being as a result of the intense session of boredom that is common after the Christmas holiday. Stay tuned, the informational flood gates will open soon. Merry Christmas.

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