Hardware Performance

[anders.hedman]

We updated recently parts of our hardware at our office. Our hardware-provider was astonished about the performance needed for getting Revit work in bigger projects without annoying delay. (He has customers using Archicad with no similar hardware demands). After discussions with the Autodesk representative he concluded that Revit doesn´t fully use the capacity built in the graphics card but base its performance on RAM which obviously has to be on the edge of what you can get in PC:s today (say 3-4 MB RAM). Does this reasoning make sense?

Autodesk indicates something similar in one article recently where they promote installation of HP:s networks computer instead of PC:s to gain the needed effiency.

Hopefully the future trend goes in the opposite direction.

Personally I often use my laptop (750 MB RAM) which works well on smaller projects but is a little bit slower in one 5000 m2 project I am starting up.

Anyway Revit has much improved our productivity thoug the drafting tempo in itself, which was quite fast using AutoCad, has been slower, partly due to hardware speed and partly to learning new commands, shortcuts etc.

We are aiming to use Revit through the whole planning process of buildings up to 10 000 m2 in size. Any suggestions for how to gain performance whitout frequent big hardware investments are more than welcome.

[beegee]

I Gb of RAM is about the performance limit for Revit.

Graphics cards don't have much of an effect on performance.

Dual processors using hyperthreading and fast hard drives are the way to go.

Project size , of itself, doesn't really affect performance. ( Otherwise, Freedom Tower would not be using Revit ! )
These things affect performance:_

1. Number of constraints
2. Number of 3d objects.
3. Compound walls and Hosted Sweeps.

[anders.hedman]

Thanks !

Small(!) misstake above: I ment of course 3-4 Gb not Mb.

Does it make some sense to build up projectparts like the interior or site in some sort of copy ( f.ex. a separate file with linked 3D-model) to limit the usage of 3D objects in the main model?

The 3D wiews and renderings could also be taken from this pararell model ( if they affect performance in the main model)

Does usage of groups affect performance in any direction?

[beegee]

Thanks !

Small(!) misstake above: I ment of course 3-4 Gb not Mb.
I
Does it make some sense to build up projectparts like the interior or site in some sort of copy ( f.ex. a separate file with linked 3D-model) to limit the usage of 3D objects in the main model?

The 3D wiews and renderings could also be taken from this pararell model ( if they affect performance in the main model)

Does usage of groups affect performance in any direction?
Lazy parsing takes care of a lot of the " normal " memory hoggers.

Groups don't have much effect either AFAIK.

Saving a rendereed image within the project file can account for a lot of overhead though. Best to export and save them in separate files.

[BomberAIA]

When I went from 1 gig to 2 gigs of ram on my laptop, Revit increased in performance. Ram is a key w/ a good graphics card and P4 HT chip.

[PeterJ]

I Gb of RAM is about the performance limit for Revit..

When I went from 1 gig to 2 gigs of ram on my laptop, Revit increased in performance. Ram is a key w/ a good graphics card and P4 HT chip.
These are rather different statements. I think it is widely agreed, looking at the benchmark tests for rendering within Revit and the experiments that have been carried out with the same deck used with 1 and 2 GB RAM, that there is a performance cap that isn't really exceeded by upping memory above 1GB. It is far from proven, that I am aware of, that in general modelling there is no improvement in performance available through increasing RAM. I'm thinking in terms of being able to move constrained objects with 12 views open and that kind of thing.

[beegee]

...1 and 2 GB RAM, that there is a performance cap that isn't really exceeded by upping memory above 1GB. It is far from proven, that I am aware of, that in general modelling there is no improvement in performance available through increasing RAM. I'm thinking in terms of being able to move constrained objects with 12 views open and that kind of thing.
You're right that we havn't got a test to show that >1 Gb RAM improves general modelling ops.

We do know that over 1 GB doesn't make much difference to rendering times though, and we could surmise that rendering is the most cpu intensive operation in Revit, so my bet is that 1 GB is where its at currently.

[hand471037]

We recommend to our customers that ask us what system they should run Revit on to get a P4 and a Gig of Ram, and there won't be much they can't do. :D

I agree with the fact that the difference between 1 gig and 2 gigs is minmal when modeling. The only difference between my former dual Xeon 2 gig system and my current P4 HT 1 gig system is in rendering time/ability. Otherwise it seems almost the same for most things, unless they are very very complex.