File Size Study

[jkrager]

Has anybody done a study and come up with a reasonable method of estimating file size of a project? Since a Revit database is essentially one file, how can I determine how big that file will get, and how do we stuff that much information through our network? Typically, I would not think this a big deal, but my office has the potential for a dozen architects working on one project, with a dozen structural, with a dozen mech, etc. With six departments all in-house working on an industrial building that the drawings are (not exaggerating) a stack of papers 15 1/2" tall. I know I can break it down into parts, but how do I estimate the size of the files?

[DaveP]

We haven't concerned ourselves too much about file size.

Sure the Revit model is big. People freak out when we say our model is 65 Meg (80,000 sq ft project). But when you sit down & figure out how many AutoCAD DWGs you would have had for a file that size, Revit ends up using less network resources, not more. Also, since 8.1, the network traffic has significantly decreased.

[jkrager]

how does that magic work? does the workstations have to be real powerful to run that? If you take that math and apply it to our size building, a 2 million sf building would be a 1.625 GB file. A 3 million sf building would be 2.4 GB. That is the range we are designing.

[sbrown]

the central file is the central file and it can get big, lets say max you'll see is 200mb. I haven't gotten above 160 yet and I think the freedom tower is in the 200 range. then the backup files, they can large, 2,3 or even 4 times the size of the central file. So if you set a quota on your jobs of 2 gigs you'll be set. You can get by with 1 gig per job, but its nice to plan some fluff. You local files reside on your local machines, so they won't fill up your network. so the number of people on the job doesn't mean a bigger need for storage. You can eat up a lot of space saving old central files with old backups, at each phase just create a new central file, delete the old ones back up and rename the old one and archive it.

[Justin Marchiel]

i heard that the freedom tower was done as a few projects, with the exterior being one, interior another, etc.

Not sure if this is true or not.

p.s. i have an adt project, 6000sf, 20 sheets (arch only), 20mb if that is any comparison.

Justin

[Wes Macaulay]

Revit doesn't read in the whole file -- it's a database, and Revit only pulls out of it what's needed for the task at hand.

But having 2 Gb of RAM is a good idea if your office is going to be doing any projects of consequence in the software -- and taking it thru to CDs.

[sbrown]

yes there are linked files in the freedom tower project, Most large projects will use linked files in some format. I believe the curtain wall system was one file, the structure another, the underground another. Basically any system that can be sep. without causing documentation errors is a good idea.

[jkrager]

Revit doesn't read in the whole file -- it's a database, and Revit only pulls out of it what's needed for the task at hand.

Can you elaborate on this a little? When the autodesk guys where here a couple of days ago, they said that Revit only downloads the model the first time you open it. After that it is only downloading the updates. This seemed to only raise more concerns from my bosses. For instance, does that mean a temporary file is stored on the local computer? If so, what is the size of that file and what happens when we have several people working on several different projects? Do the temporary files pile up in their hard drive?
I could not begin to try to answer these questions because my revit files have been small projects. I do not know what the implications are when it is magnified across dozens of people with much larger projects.

[DaveP]

If "the autodesk guys" were there, I'm surprised they didn't answer some of these questions. Sounds like they didn't explain Worksets very well.

When you have multiple people working on a project, you need to enable Worksets. Once you've done that, you save that model on the network as a Central file. Each user then makes a copy of the Central file on their local hard disk. You typically just copy the Central to your C: drive, so it's exactly the same size as the Central. This isn't a "Temporary file", its your copy. Then, whenever you go to edit something (say, move a wall), Revit looks at the Central file to get permission to edit that element. Once you've got permission, no one else can edit that element.
The changes you've made stay on your local copy until you "Save to Central". At that point, the changes you've made get pushed up to the network, and the reconciled with the changes everyone else has made. Only the changes get pushed back and forth, so you're not throwing a huge file around. You only need to do that once - when you first make your local copy. You'll typically Save to Central between 1 & 3 times an hour.

BTW, my 65 Meg file is post-construction and has a whole bunch of ASIs and PRs in it. Our Revit Template with all our standards and families built in is about 8 Meg. So if you're going to scale that 80,000 sq ft to 2 million, you'd probably want to use about 50 Meg, not 65. That's still 1.25 Gig, but it's not necessarily a linear scale. You say your project is an industrial facility, which I would guess is going to be a lot less dense than our Medical project.

[jkrager]

To give the adesk people credit, we came at them with some tough questions and a bit of skepticism. Honestly, the people here have more faith in Revit than the salespeople did, but that is another thread completely.
I am playing devils advocate a little :veryevil: (sorry if i step on your toes cosmic) because these are the kinds of questions that our autodesk support team will need to answer to get Revit into this office. I did some research on our server, and currently it takes 181.38 MB of space for our Triforma models, the extractions to 2D, and the autocad background and sheet files for one project which includes arch, struct, and MEP. It seems that a Revit footprint, though larger, will still be manageable on our network and the estimations made by the skeptics are not realistic because as you say it is not a linear scale.
It is fustrating that everyone is waving the Freedom Tower as the Ultimate Revit example, but there is very little information out there as to how it is actually working. Perhaps that stuff is secret, but it sure would be nice to hear concrete examples of specific applications. I appreciate all the input here. In fact, this group might be one selling point to help the autodesk cause here....hmmm.

[sbrown]

the only reason I mentioned the freedom tower is because of its size. I've had small 5000sf buildings with lots of detail take up more space than 200,000sf distribution centers. The file size takes some management, but never NEEDS to be larger than the central file size on the server(for each central if you have multiple building models on a project) + the size of the backups(which you have control over the number) + your project library. Here is an example of the largest project I'm working on. Its in DD, its only about 180,000sf but the level of detail, custom families, ironwork, stone work, trim, tables, chairs, furniture, etc. is the most I've personally ever seen in a revit job. The central file is
currently 154mb, its been as large as 194mb, the backup file for it is 334mb(set to 20 backups). The library of families is 224mb. The total space for all drawings(exports for consultants, civil backgrounds etc is 1.54 GB. So the percentage of revit stuff at about 1 gig. The exported dwg DD set is only 30 mb (arch only). I forsee the final CD model being 3 times this size based on my experience with smaller size cd sets. They are typically 2-3 times the size of the dd set due to the significant amount of sheets, details, views, annotations, etc that will go into the cd set. So my guess when its all said and done is I will need around 4 gigs for this project.

[Scott D Davis]

File size in Revit is completely dependent on the level of detail. Ultimately, and 3,500 SF house could be a larger file size than a 2 million SF warehouse building. It is definitely not linear, and there is really no way to calculate what a file size might be.