Slow Opening Revit Model?

[mdavislv]

I am working on a large Revit project and being new to Revit I have a major question regarding the time it takes to open a model (and associated links).

The project I am working on has roughly 600 MB worth of Revit links (Arch, Foodservice, Struc included) and our model that's 57 MB. It is currently taking us roughly 5 mins to open our local Revit model with all of the links loaded in it. I'm not sure if this is pretty good as I have no other large project to base this off of. I am currently using the following hardware:

HP Z800 Workstation

Windows XP Pro x64 Edition

Inter Xeon 2.40 Ghz/2.4 Ghz

11.9GB Ram

256 MB Video Card

Using Workshare monitor I can tell that Revit isn't using more than 30% CPU and less than half of the RAM so I know it's not a hardware issue (from what I can tell). We are locating our "Local" files on our network drive as I have been having a difficult time getting people to synchronize on a regular basis and I worry a hard drive failure will lose alot of production. Not sure if that may be a leading cause?

I understand that the project is massive in size (not even into CD Docs yet) and that there is alot of info that the PC has to open but I am getting pressure from project managers in our office that I must be doing something wrong for the models take this long to open. Yet, they know nothing of Revit and are still basing everything on AutoCAD production times.

Thank you for your time!

[CrazedEngineer]

First you should say a silent prayer, because it is only taking 5 minutes. 

My company has models that are over 200,000 KB(Just the Interior Model).  And the models have taken over 45 minutes to open. 

There are a few things that can help you speed everything.

Easiest step being.  Create a seperate workset for every link(Revit and AutoCad) you have, and place go through the model, and place the link on the apprioate workset.  This will allow you to open the project and specify which workset you want or need to turn on.  (ie say you are in the electrical model, and you have a shell core model, a interior model, a plumbing model, a mechanical model.  And you only need the sheel core and the interior model turned on, then you can specify that only those two worksets load, and it will speed up your opening time dramtically.

The other steps go much further. Once we got to a certian size for our electrical models we started spliting the model by disclpine.  It got split to Power/Lighting(Requring circuiting) and Fire Alarm and Comm.  Then once the model again got too large to manage, we started splitting those models by floor. We also made a seperate models just for details and legends(mind you if you do legends you can't use legend components, you will need to use generic annotations. )

There is much more you can do.  But these were the ones that we noticed made the largest difference.  Once you split models it does get harder to manager and make global changes. For us the manging time took a back seat to the hours and hours of lost productivity  we had from just saving and opening the files up.  But there are tricks to that as well, such as opening the model with no worksets on, and loading the updated family into all the models.

Hope this helps.

p.s.  Also have everyone to stop streaming the World Cup online.  It ties up the network and makes your load and save times unbelievablly long.

[CrazedEngineer]

There is also a white papaer out there that I have seen about large model performance and the best way to manage them.  I will see if I can find it.

[asommer]

Crazedengineer is right, I have a project under 200 MB, it takes 20 minutes to open (2009).  Yes, tell your project managers to go get you a cup of coffee while you are waiting the 5 minutes.  By the end of the project, you'll be drinking liquor.

One thing I noticed, if you split ducts and pipes where it is convenient, it will cut the calculations short, therefore it will run faster.  on a large project like that, you probably aren't using the calcs anyway.

Looks like you have the right machine for the job, as long as it's not giving you any warnings.

[mdavislv]

We are currently using one model for MEP (only 57 MB thus far). It is my understanding that connections cannot be carried through from a linked model (i.e. the Electrical model cannot see the power connections on our equipment in our Mechanical model), is this correct?

I do understand though that we are not using Revit to its full benefits. Upper management did not want to utilize Revit to help in calculations so we are pretty much drawing "dumb" systems that do not carry through cfm, static pressures, etc. "Collision Detection Only". Not sure if that could be helping, hurting, or indifferent in this matter...

I also have started Purging all of the consultant's models prior to linking them in our model but noticed that in one instance a 100 MB file bumped up to a 110MB file after purging. Should I compact their file as well? I also noticed that some of the linked models have missing references to CAD files they are using in-house that we do not have. Is it possible that they may also be slowing down start-up times due to having to look for the referances and "timing out"? I know this can sometimes be an issue in other Autodesk products.

Thank you for your time!

[asommer]

You are right on track.

No, the calcs will not carry through from a linked model.

The revit will try to calculate the flows and pressures and such automatically, and cannot be turned off.  The larger the system's connected mass is, the longer it takes to recalculate when you make a change to it.  That's one of the big slowdowns.  We did the "dumb" systems on our first big jobs, it saved alot of time.  2011 is giving an option to stop the calcs for the electrical systems, maybe one day it will be for all.

Yes, Purge all links.  If the linked file has missing references, it will try to load them, then it will warn you about it every time you open your model.  I Audit the consultant's model when opening, Remove ALL unused links (Cad and Revit) from the model, purge it, and compact it.  Every little bit helps.  I don't know why the file got larger when you purged, keep an eye on that one.

Good Luck!

[TexasJetter]

If your main concern is simply the time it takes to open a model there are a couple of things not already mentioned here that may help.

How the model was last saved makes a big difference when opening it the next time. It is highly recommended that you make a drafting view, most people put some generic text like "Use this view when saving".  Make sure everyone gets into the habit of switching to this view and close all other views before saving to central.

Doing this will make the opening view your simple drafting view, so minimal elements have to be generated when opening the file.  The worst thing to do is save to central when you have the 3D full model open.

While this technique will help a little, taking 5 minutes to open a Revit model is not abnormal...

[CrazedEngineer]

I also do the same thing that TexasJetter suggests.  It does help alot.  I have also made that mistake and did a save to central while in a 3D view of the entire building.  I ended up going home for the day and letting it run.

[JSmith33]

Attached is the technical performance white paper that "Crazedengineer" referred to in his post.  There are overall Revit platform related suggestions, as well as a section specific to MEP.

Also, to add to all of the excellent suggestions here, I wanted to reinforce that placing strategic breaks in large duct networks is one of the best ways to improve performance in a MEP model, as this will reduce the time needed to calculate flow through the entire network.

[anna-maria.malla]

This is an old conversation but I am sure many people still face the same problem so I have something to add to it since we faced this problem in our office recently. The problem was that we made the linked models Room Bounding (Select the link, click on Edit Type and tick the box for the Room Bounding Parameter). It was nice not having to draw room separation lines to create rooms but all the Revit users suffered from errors, Revit crashing and very long times of opening the file and synchronising. The problem was resolved when I deselected the Room Bounding option. Drawing room separation lines is faster. I hope that helps.

[RinaBean]

How do you save it like this?

[RobDraw]

TexasJetter made that post in 2010 and explained the process very well. If you are having performance issues, I would suggest posting a new topic as this one is quite old.

I will add that you have the ability to assign a starting view to open every time the model is opened. Check the manage tab for setting a starting view.