Revit File Size Limits

[swalton240189]

We have a large project ~275,000 SqFt. It was started in Revit 2009 32bit by people relatively new to Revit.
It is one
1 - in-house new architecture model (250MB)
1 - existing neighboring building with limited work (21MB)
1 - In-house MEP 3D Model (78MB)
1- In house MEP 2d/detailing Model (25MB) This is separate from the 3D because of slow performance.
1 - Site Model (25MB)
1 - Mockup for the contractor to construct in a parking lot (15MB)
1 – Consulting Structural Engineer’s Model (42MB)
(All of the file sizes are after compacting the central file.)
The MEP and Arch file are linked to each other through detached files that are updated/replaced 2x per week. This helped performance a lot.

The whole team is on Revit 2009 x64 with 12gb of ram recently upgraded from 8gb because of not enough memory to open project warnings. They all have Core 2 duo or Quad core chips with vista business 64. We have a 100Mbit network.

At any given time there may be 10+ people in the arch model and 3 or more in the MEP model. There are a lot of error warnings in each model but we feel it may be too burdensome to clean all of these up. The users are much more experienced now that they are in the 6th month of the project so fewer errors are being generated.

Performance is slow and save to central times can be 10 minutes at times.

The 12GB seems to have got the project to open but with 2 months and a lot more 2d detailing to go I’m worried we may need to go to 16gb.

I guess my questions are.
1. What is the performance bottleneck the CPU, RAM or Network Speed?
2. Are there too many people working in one file?
3. Other than the tips on AUGI about reducing file size how are people dealing with revit projects over 200,00sq. ft. / 20,000 sq. m.?
4. The old rule of thumb was for every 50mb of file size you need 1gb of ram does that hold true when you get past 150mb? Does that include all the linked and loaded file sizes or only the open file?

Thanks

[twiceroadsfool]

While there is SOME correlation between size and performance, it is certainly not the only defining factor in terrible performance.

By *there are some warnings* how many do you mean? Ive seen these DRASTICALLY slow down files, while Revit sits there and ponders constraints, joined geometry thats not joined, lines off axis, etc.

FWIW, ive had 1.8m SF linked together in a bunch of Revit ARch Models, and i was just experiencing the need to have a g4 bit machine to open them.

The last set i did in collaboration totalled about 460MB, for about 480,000 SF. The 32 bit machines with 3.25G of RAM had trouble opening them, but even then it was workable... But we kept the warnings low, and keot the files in generally good shape...

[swalton240189]

By *there are some warnings* how many do you mean? Ive seen these DRASTICALLY slow down files, while Revit sits there and ponders constraints, joined geometry thats not joined, lines off axis, etc.

In the arch model there are about 2,000 errors. 400 of which are lines slightly off axis.

There were a lot in MEP (too many elements on the default system) but they did a good job cleaning them up. That helped MEP run better but since they always have the arch model linked in and open they are still running pretty slow.

Some posts have suggeted saving to central more frequently would this help?

Everyone gets fresh local copies every morning. That seems to help a lot.

[twiceroadsfool]

2000? Wow. Thats going to kill performance. If you go in there, with that quantity a lot of them HAVE to be redundant, and you can probably clean them out in a day. Ill bet you see huge gains from it...

In my limited experience, warnings about things detaching, or unjoining geometry , or room voluming / area / enclosure ones are the worst...

[Steve_Stafford]

...400 of which are lines slightly off axis...From exploding cad details I assume? Do that in a detail component family instead. Add text and dimensions in the project's drafting view over the detail component. The errors are "trapped" in the detail component instead. Long term you are better off with cleaned-up native Revit details.

[truevis]

Make sure users always specify which worksets to open when opening their locals.
Locals are created daily, right?
Worksets have been determined with performance in mind, right?
4 pax max on one RVT, IMO.
Fix most warnings.
Eliminate & minimize CAD stuff if possible.

[swalton240189]

From exploding cad details I assume? Do that in a detail component family instead. Add text and dimensions in the project's drafting view over the detail component. The errors are "trapped" in the detail component instead. Long term you are better off with cleaned-up native Revit details.

Some of them may have been tracing CAD details but most were things people made as detail groups instead of detail components then they prolifereted around the model.



[LIST]
Make sure users always specify which worksets to open when opening their locals.
Locals are created daily, right?...
4 pax max on one RVT, IMO....
LIST]

they do specify which worksets when opening.

yes fresh locals daily.

Is that 4 people per worksetted file? The Arch can have up to 16 people at busy times. There are people available and a deadline looming so for better or worse they are throwing a lot of people at it.

[twiceroadsfool]

Eesh... Invest the time and get it cleaned up over the weekend. Detail groups instead of detail components is sure to bog everything down a good bit. The warnings arent helping.

16 people in a 280k SF building? I hope thats an extremely complex building, because thats a lot of hands in the pot at one time.

FWIW (not much) i dont believe the "throw people at it" solution works in Revit the way it did with drafted drawings... Its too easy to turn a model in to a cluster. And since youre not drafting, youre building, you really have to be engaged and 'know' the project to be in there editing things... Or sloppy precautionary methods have to be taken. Just my two cents tho... :)

[truevis]

...Is that 4 people per worksetted file? The Arch can have up to 16 people at busy times. There are people available and a deadline looming so for better or worse they are throwing a lot of people at it.Yes, too many people in one RVT is probably your primary problem. I concur with twiceroadsfool; a small team in close communication is ideal.

Can you tell us more about your experience with having so many people working on one RVT?

[swalton240189]

Yes, too many people in one RVT is probably your primary problem. I concur with twiceroadsfool; a small team in close communication is ideal.

Can you tell us more about your experience with having so many people working on one RVT?

I'm in more of a BIM support role at the moment so until recently I wasn't really in the file that much. Now I'm trying to clean up as many warnings as I can. The save to central procedure takes about 3-4 minutes in total. We always navigate to a drafting view and close other windows. Save Local. Reload Latest. Save to Central then save local. The reload takes about 2-4 minutes depending on how long since your last reload. Save to central only takes about 20 seconds.

Performance isn't too bad as far as placing or modifying elements but is definatly slower than other projects with fewer people. Many people are just detailing so generally not borrowing model elements. Supprisingly there isn't that many people borrowing elements that other people end up needing.

[BIMTom]

my first target would be why the file size is so big to begin with. I've seen hospital models three times the square footage with half the file size.

[swalton240189]

my first target would be why the file size is so big to begin with. I've seen hospital models three times the square footage with half the file size.

My suspicion about the file size is a combination of errors, 16 users at a time in the file generates a lot of history/backup information, lots of detail groups instead of detail components.

On those large hospital projects do you model your equipment components in, 3D or for the ones that won’t need to be shown in 3D or renderings, do you do them as detail lines in plan and elevation?

[Scott Womack]

Sean,

The 64 bit version of Revit 2009 still has limitations on how much Ram it can access. Someone from the factory can correct me if I'm wrong, but essentially, the 2009 64 bit version is a "port" of the 32 bit version to a 64 bit operating system, and as such has some Ram access limitations. These do not exist in the 2010 version, since it was a native ground up 64 bit application.

[swalton240189]

my first target would be why the file size is so big to begin with. I've seen hospital models three times the square footage with half the file size.

As an experiment I wanted to test how much file size would be reduced by deleting checked for all the error causing elements that couldn't be fixed automatically. I started with a 303 MB Compacted Central File. After getting the warnings from 1787 down to 36 warning by "deleting checked" one item from every warning. Some had no check box that's why the rest of the warnings remain. After doing a save as this only decreased the file size down to 288 MB that's about a 5% decrease. Better than nothing but I had been hoping for more. Especially because not all of this reduction is fixing warnings a fair amount was the elements being deleted. It does however seem to be running a little smoother but not drastically.

My new thinking on the file size is that it is a lot of detail lines and filled regions in all the views instead of detail components.

There are 201 sheets which doesn't seem especially high.

BIMTom was there a lot of detail in those hospital projects? A lot of equipment/ furniture included?

We have not that much furniture but exercise equipment, and floor finishes modeled.

[truevis]

...We have not that much furniture but exercise equipment..

Be careful with families like that. Check how they are made. Are they made from some CAD import? Keep them as simple as possible.

I once made a family for an exercise bike made from something I got from Turbosquid in 3DS, which I converted to DWG. In Revit it was fine (only needed one), but in a DWG export, the bike contained like 10000 lines.

[twiceroadsfool]

As an experiment I wanted to test how much file size would be reduced by deleting checked for all the error causing elements that couldn't be fixed automatically. I started with a 303 MB Compacted Central File. After getting the warnings from 1787 down to 36 warning by "deleting checked" one item from every warning. Some had no check box that's why the rest of the warnings remain. After doing a save as this only decreased the file size down to 288 MB that's about a 5% decrease. Better than nothing but I had been hoping for more. Especially because not all of this reduction is fixing warnings a fair amount was the elements being deleted. It does however seem to be running a little smoother but not drastically.

My new thinking on the file size is that it is a lot of detail lines and filled regions in all the views instead of detail components.

There are 201 sheets which doesn't seem especially high.

BIMTom was there a lot of detail in those hospital projects? A lot of equipment/ furniture included?

We have not that much furniture but exercise equipment, and floor finishes modeled.


Again, keep in mind that File Size and File Performance dont always correlate, but in this case there are a lot of things you can still change, that will probably contribute to ficing both.

Detail lines/Detail groups in Plan for equipment and objects. This is SURE to be bloating the file size. Everyone on the team needs to remember, the power of Revit is OBJECT oriented, not 3d-complex-over-modeled-oriented. If you dont need it in 3D, thats fine. MAKE A FAMILY, and put symbolic lines in the plan. Use the FAMILY instead of the detail groups, and the rewards are far reaching. Smaller file size, better performance (its not monitoring the groups for inconsistancies). I think Dave B. has a blog post on the difference, which he quantified for a very small object. He drew it in the model, versus drew it in a family, etc. The file size difference was considerable, give then tiny nature of the example. Plus, the families will respond to correct Object Styles for lineweights, etc.

How many of the components you have (as mentioned) are imported DWG geometry? Or imported SAT file geometry? In my experience, these slooooooow performance down a decent amount. If you need them for rendering, you need them for rendering, but consider doing the following: Make two versions of the families, one that has the complex imported geometry, and one that has a generic but properly sized extrusion, without the complex model. It can even have detail components to show properly in plan and elevation. When you need to render, swap them out for the cad-import-family. (OR do it in max...). But theres no reason for all that stuff for documentation, its just slowing you down.

[Phil Read]

In the arch model there are about 2,000 errors. 400 of which are lines slightly off axis.

Ouch. This can create significant graphic regen, printing and computational overhead. If you get this warning - it's usually not from tracing. It's from picking lines (for example - picking lines that exist in a linked CAD file in order to create walls). If you get this warning - stop picking lines and start sketching.

There's no way to automatically fix this error (API/Macro/etc). And the downstream implications from not fixing can snowball.

-Phil

[travismv702230]

And, another thing about the lines slighty off-axis that will kill you is when you get to dimensioning. I had that issue in a project and I had to basically kick everyone out and go back item by item to fix it. We had things off by 0.0046 degrees. It took me about a day to fix. Caught it in SD-early DD. The base file for the building layout was drawn in AutoCAD. Absolutely, positively make sure it is drawn correctly if you are going to pick lines.

[NKramer]

Does anyone have any evidence to say whether additional views (3d, elevation, etc) increase file size?

I have heard both ways. I know additional detailing, drafting and view specific items will add to file size, but what about 3d and other views that are reference only?

Nick