xrefs - how much is too much?

[jpduhon]

wow!

A user just came to me panicking about his CAD file. I took a look and noticed all the xrefs loading... and they just seemed to keep loading.

When it finally opened I saw what is shown in the image below.

So this leads me to two questions:
1 How many xrefs is too many?
2 What are you telling your users to do when xreffing? Overlay, attach or are you not managing this?

[Mike.Perry]

1 How many xrefs is too many?

Honestly depends on the type of project.

Also a key considerations, is the hardware being used up to the task ie.

* Is the network up to the task of transferring *all* that data to the desktop computer requesting it, in a reasonable time frame.

* Is the desktop computer able to load *all* that data into memory in a reasonable time frame and still be functional / userable...

2 What are you telling your users to do when xreffing? Overlay, attach or are you not managing this?

Always use Overlay, unless the task at hand is *only* achievable via Attach.

Have a good one, Mike

[zoomharis]

wow!
1 How many xrefs is too many?

How many drawings can you open in your AutoCAD at a time? Your question is almost same like this. I would say that depends upon the machine & software configuration as Mike said.

2 What are you telling your users to do when xreffing? Overlay, attach or are you not managing this?

We already have a very good discussion on that topic over here

HTH

[Mike.Perry]

Hi

Additionally, you may wish to take a look at THIS post and THIS one.

Have a good one, Mike

[Buffeldrek]

hi - we have a drawing too with numerous nested and overlay'd Xrefs - in total about 50 to 60. When opening this drawing the computer memory goes up to 2Gb. And that for an AutoCAD drawing. I had to put the /3GB switch on that machine. Takes a couple of minute to load too.
It is our compagnie Geo drawing. And yes, we need very performant hardware to handle this, choosen a workstation for it.

[cadtag]

dang, with that level of complexity and amount of data, y'all might want to think about moving it into Map3D, and use drawing sets and queries instead of Xref files....

[Buffeldrek]

it kind of grew over the history - everything outside the building is on map - all inside the buidings was put in autocad vanilla with the xrefs.
Offcourse now we stand - relalizing that wasn't the best idea...

[Avatart]

That Xref list looks pretty typical for one of our projects. I don't think that there is necessarily a limit to the number of Xrefs, it is how you manage them that counts. Also, there is a point where it is better to use a Block rather than an Xref, my general rule is; if it is not likely to change too much and if the drawing falls apart without it, use a Block (eg facade cladding units I Block in, a whole facade line I would Xref in).

If the computer is grinding, then I would look at the hardware, rather than change the way in which I construct my drawings.

I always use Xref Overlay, we have had so many problems with Attach Nesting creating mutliple instances of an Xref, then it is a nightmare to remove it. It does create a bit more work, but the payback is that your drawings do what you want them to.

[kleenhippie]

That list of xrefs looks pretty tame. I have gotten dwgs. from one engineering company in particular that xrefs every Architectual and Structural dwg. into each MEP dwg. We're talking 24 story condo buildings. I can open a Penthouse dwg., and see everything in the underground garage levels in model space. Everything is controled by freezing layers in paperspace. But when you're used to working in model space it's really a pain. I end up making up my own architectual backgrounds to use. Seems like quite a waste of time on my end.

[jpduhon]

Well, thanks everyone for the responses. Mike's first response

Always use Overlay, unless the task at hand is *only* achievable via Attach.

along with the links to the other posts really was what I was looking for.

I've been telling users this for years but I always have to help projecs that are having xref problems and are too far along in the process to effectively go in and correct things. Then when I try to explain why it's neccessary to only use overlay (at least in almost every case) I get the paradigmatic responses, "We've always done it the other way" and "We never had a problem with it before" or "That's so much more work to xref everything into every drawing".

Is there some documentation out there that can explain things more concisely to users?
Maybe this question is better for the LISP thread but is there a way to require overlay vs, attach programatically?