trouble opening certain files

Please forgive me if this question has been answered elsewhere in the forum, as I was unable to find anything like it and I'm beginning to get frustrated.

I'm self taught with the ancient AutoCAD 2000, and learned much of what I know on CAD Tutor (thanks everyone! ).

I'm having a problem whenever I try to open certain files. (All of our files are .DWG, so I suppose I mean files with certain contents) In my office, we work a lot with aerial photographs, and I'm having trouble opening CAD files with a number of aerial photographs. I've looked into file size being my problem, but I can open other files that are almost nearly identical in size with no problem at all.

I've also noticed that it will happen with a file that I just created, plotted, even plotted via PDF. As soon as I close the file and try to open it again, it won't open. The same thing happens with files created by my predecessor.

When I go to open one of these problem files, they begin to load like normal, and then before all of the images have been loaded, I hear an error tone. There's never any message, but as soon as I hear the sound, it's all over. And sometimes, it gets all the way to the end, loads all of the images, and I see my document for about a half of a second, and then the same thing. Error tone, and I can't see anything, just a blank white screen like when CAD is first starting up.

Worst of all, I can close and/or minimize all other applications I have running EXCEPT AutoCAD. It behaves like my computer's frozen, but only with CAD. I've also tried to open these files when all other applications have been closed, with no success.

Any advice would be greatly appreciated! Thanks in advance!

Are there xref's attached to these drawings? If so, try opening the xref's and run an AUDIT on each of them. Then try opening the main drawing again. If it opens, run an AUDIT on that file also. It could be that one of your files contains errors that is causing these problems.

Another possiblity could be that you are running out of RAM. What are the specs on your computer?

Don't make too much fun. I am by no means an IT person, but I'll do my best: i've got a pentium 4 processor, it says 3.60GHz 3.59GHz, 1.5 GB of RAM, and it looks like 37.1 GB of FREE space on my C:/ drive. I'm working with Windows XP (2002 version).

(From my "view system information" button in "my Computer")

Negative on the X-ref's.

Ok, you're a little light in the RAM department, so you very well could be running out of memory.

So, exactly how big are these files and how many images are in each file? Also, are these images tif's or jpg's? If they are tif's, you might want to consider converting them to jpg's which carry a much smaller file size. Autocad has trouble with images, and when you put a bunch of high resolution tif images into your drawing, it can bring even a good machine to its knees.

ahh! Now it all makes sense. You're awesome!

I'll be sure to tell the powers that be that I need RAM. I know someone will be impressed that I know that. :wink:

I was always told to convert my files to .tif. Does it make any difference to the final product if they're .tif or .jpg?

The file I've been trying unsuccessfully to open today is 1,217 KB, but it's got 35 aerial photographs, all of which are 1 square mile. I've got another file thats 1,214 KB, with four images (not aerials), that opens almost instantly.... no problems at all...

Is it just based on resolution then?

Wow! I'm surprised your machine can open those files at all. With 35 huge tif files in the drawing, Autocad is probably using every bit of available resources.

Converting the tif files to jpg will cut down the image file sizes considerably. You might notice a slight decline in image quality, due to compression, but for what you're using them for, I doubt it will make a difference. But due to the size and quantity of the images, you will probably still have problems unless you upgrade your RAM.

So go impress your bosses with your new found knowledge. Tell them you need to max out the RAM in your machine. If you're running a 32 bit operating system, then you should be able to install 4GB RAM. But you will have to set the 3GB switch in order for your system to access the extra RAM.

See here: http://dwf.blogs.com/beyond_the_paper/2009/04/enabling-3gb-switch-on-windows-vista.html

And if you're running a duo core processor, be sure to set your Autocad WHIPTHREAD variable to 3. This will allow Autocad to use the other processor to help out when regenerating views.

Thank you!