What Computer Makeup is Recommended with Revit

[artitech]

I'm not talking about beauty products, I was wondering what everyone else is using / finding works best for performance when running a Revit project?

I am suffering heavy loss of time and have lost information daily due to crashes while I've been putting my architectural thesis project together on Revit. My building project file is 34 Mb and my Site file is 8 Mb in size. I literally had to cease making changes to my toposurface due to time loss and crashes.

I have a Pentium 4, 3.06 Ghz, 512 Mb RAM, 120 Mb HDD (40 Gb Free) and NVIDIA GeForce FX 5200 128 Mb video card. Pretty basic stuff these days.

What is everyone else using - and what seesm to work best? Is there a new standard for Revit users?

[artitech]

I should add, I kept getting this message....

"The current session is using more memory than this computer can efficiently support. This could be slowing down some operations"....

... adding more RAM to the computer was identified as a potential solution, but is that enough and how much is recommended?

[Martin P]

Do you regularly close all hidden windows? I found that doing this helps with the ram error messages.....

But that does look a big project!

We have no problems with dual processor P4 - 1GB Ram and we just run on the onboard Intel graphics cards, apparantely Revit doesnt make much use of fancy graphics cards (or dual processors for that matter).....

The dual processor helps if we have more than one Revit session open (I think) which as you will know you need to do with linked files when editing them, and also when rendering.

We dont use a lot (well any really!) of Site data in Revit, maybe it uses a lot of computer power to do a lot of it?

[Les Therrien]

I wouldn't say that's too large a project. Average maybe!?
From what I could see at this end, I would say you're lacking in RAM.
The recommended use to be 1Gig. I think it's up to 2 Gigs now!?
Revit is a great tool but it takes a lot of time processing. This is my biggest gripe!

[BWG]

Better get 2 GB of RAM for that project if you want to finish it out. If it is close, 1 GB should be enough. I have 512 MB in my home computer and it barely will run Revit, just doing small projects. I don't think Revit is any more a memory hog than any other program. Take a multi file project in other programs (ADT, DC, SP, MS, etc.) and open them all at once and try and make it work similar to revit, including rendering - You will crash your system just the same if you don't have enough RAM. Rendering really eats up the RAM, and all rendering programs will do that.

[Millett]

The issue is probably memory. We have done up to 120 MB projects with up to 8 Revit users. We use 3.4 MHz Pentium 4s with 2GB memory and 128MB graphic cards. Though saves to central can be slow these machines get the job done. I assume you are using Revit 8 which we've found much more stable than Revit 7. I also assume you have not created a central file. We found that Revit performs worst when you have a central file and local file located on the same computer.

[FK]

Yeah, you want to run at least one gig of RAM.

By the way, running two copies of Revit to edit linked files may theoretically confuse the thing, and is not recommended. That's why one instance will not open both files simultaneously.

[Martin P]

Yeah, you want to run at least one gig of RAM.

By the way, running two copies of Revit to edit linked files may theoretically confuse the thing, and is not recommended. That's why one instance will not open both files simultaneously.


Works fine, honestly! ;) never caused me any crashes yet. But I can see it may not be recommended by Revit Developers!!... but it will work, sometimes saves an awful lot of time opening and closing files..

[artitech]

Sounds like a minimum of 1 GB RAM is the recommendation.

I would like to know what the Revit developers feel about the dual-processors, do they make a difference running a session of Revit?

This will help me on future computer purchases / updgrades.

Thx.

[Allen Lacy]

Sounds like a minimum of 1 GB RAM is the recommendation.

I would like to know what the Revit developers feel about the dual-processors, do they make a difference running a session of Revit?

This will help me on future computer purchases / updgrades.

Thx. From what's been said here before, Revit itself does not benefit from dual processors. However, Accurender can take advantage of dual processors.

[mmodernc]

There it is again-the old editing linked files issue. What is the technical explanation for Revit teams reticence?

[BWG]

From what's been said here before, Revit itself does not benefit from dual processors. However, Accurender can take advantage of dual processors.


Doesn't dual processor work in such a way that when processor 1 maxes out, then processor 2 kicks in?

[Scott Hopkins]

If the application you are running is multi-threaded, dual processors will work together to increase performance. If the application (Revit) is single treaded then only one processor will work at a time.

[artitech]

Scott,

That's an intelligent answer.... how do you determine if software will run multi-threaded? This would be a good thing to understand.

Also, can you comment on whether it's worth getting a graphics card more than 128Mb for running Revit? Is there any advantage to a 256 Mb video card or better?

Thanks.

[iru69]

how do you determine if software will run multi-threaded? This would be a good thing to understand.
Ask the developer? Not too many desktop applications runs multi-threaded yet... mostly been renderering software.


Is there any advantage to a 256 Mb video card or better?

No - according to FK (one of the developers):

Yawn... the usual. Huge video RAM is for games, 64 megs is more than enough for Revit.
You can read more about video card requirements in these threads:
http://forums.augi.com/showthread.php?t=17027
http://forums.augi.com/showthread.php?t=17157

[neb1998]

I have found that 4 gigs of ram is a good amount for large projects, especially while working in 3D or with shadows. 1 gig of ram seems to work fine on projects under around 5k square feet. 2 gig of ram good for larger than that - but as with any computer, more cant hurt.


AMD FX-55 processor
4 gig DDR ram
NVIDIA FX-1400 video card
RAID 0 - SATA 75 gig harddrive array

[FK]

Cool, I get to make one answer to two questions.

The problem is concurrency. If you try to carry out two actions on the same object at the same time, you will get unpredictable results. So, if one copy of Revit is trying to write a file, while another is trying to read the file, the other may get profoundly confused as the file changes under its feet. Likewise, if one program executes on two processors at the same time (each processor running its own thread of execution) and both processors try to access the same memory location, anything may happen. So, in both cases the programmer has to make a disturbingly elaborate dance to make sure things don't step on each other's toes.

[Les Therrien]

That is interesting.
But then how do other programs take advantage of two processors and not have that problem?

[Lashers]

Maybe its Mabeleen!

[FK]

That is interesting.
But then how do other programs take advantage of two processors and not have that problem?
Why, they do the disturbingly elaborate dance of course.

Some problems are naturally "parallelizable". A ray tracer, for instance, will do fine if CPU 1 is computing the color of pixel A while CPU 2 is computing the color of pixel B.

Databases have to ensure pretty rigid properties known as ACID (Atomicity, Consistency, Isolation, Durability). That's a subject of deep research and subtle engineering gotchas.

For instance, to make sure simultaneous processes don't try to mess with the same thing, we guard the common resources with "semaphores" that indicate that a resource is busy.

So, process 1 needs resources A and B. It raises the semaphore on resource A.
In the mean time, process 2 needs resources B and A. It raises the semaphore on resource B.
Process 1 tries to raise the semaphore on resource B, but that's already occupied, so the process waits until it's released.
Process 2 tries to raise the semaphore on resource A, but that's already occupied, so the process waits until it's released.
This is called deadlock.

So, let's modify the behavior: if the second resource is occupied, release the first resource and try again.
So, the processes constantly acquire and then politely release the respective semaphores, trying to let each other proceed, but never going forward.
This is called livelock.

If you google for "dining philosophers" you will see how this can result in death by starvation and why lefties are necessary for the survival of science.

[Les Therrien]

great info.

thanks!

[Wes Macaulay]

I missed the last few posts in this thread. FK makes me feel so good that God made me left-handed. Up til now I thought I was only in league with people like Nixon, who was famous for clobbering himself via his left-handed clumsiness.

Now all I have to do is figure out my contribution to science...

[gbrowne]

Yikes! Programmers...Sounds like scary stuff..

Did we establish what computer makeup is recommended?

[FK]

Juxtaposition of "computer" and "makeup" is calling for a pun, but I'm failing to come up with it.

[gbrowne]

It is?! Is that a programmers joke.. ? Thats exactly what I was saying...haha.

And Fedor, keep up the good work, or to use a pun:

Stick to your day job... ahahaha!