I've got AutoCAD 2006 and I'm working with some pretty large 3D models. After adding more and more complexity to it, AutoCAD keeps crashing more and more frequently. The file size is a little under 100 MB and I've got 2GB of RAM on my 5.66MHz dual processor machine. These are some of the typical problems I'm getting: -error message saying "FATAL ERROR" -error message saying "Not enough memory" -AutoCAD just freezes -Rendering just stops half way through processing If AutoCAD has to shut down, it usually gives me the option of attempting to save a recovery file before exiting (which doesn't work - it crashes when I load it). Sometimes, it also lets me write up an error report to send to Autodesk. My best chances of rendering my model are just after rebooting my computer, starting AutoCAD, loading the file, and saying render right away (especially if I have shadowing off and other options that take up more time) - but it seems like the more steps I take (rotating, zooming, playing with layers, etc.) the more likely it is to crash when doing something heavy like rendering or saving. To me, these symptoms seem like a problem with too little memory. But I've got 2GB! Isn't that enough?! The AutoCAD specs for 2006 say I should be able to get away with 1GB. The file itself is only 100MB - how could it take up more RAM than HD space? Is it possible that there are some memory leaks in AutoCAD? This would make sense out of how it crashes more often after doing several steps.

Autocad is a memory-intensive application that works best when you have nothing loaded in XP Startup. I also assume that the PC meets or exceed the AutoCad System Requirements set forth HERE. To find out what you have loaded in the Startup, press ÿ+R at same time. This will bring up the Run prompt. Type in MSCONFIG and hit Return. Click on the Startiup tab. Disable everything. i_XpUser

When y9ou are done, save & exit MSCONFIG. Reboot the PC and try AutoCad again. i_XpUser

as XP said Autocad is memory intensive. However, I am at work with the government on a windows 2000 professional maching with only 500 MB RAM and Autocad still works .. I have been all over the IT personel to install at least 1gig of RAM like I have on my home machine. The Govt. just won't put up the money give me a machine which won't freezeup every time i run autocad. Especially when I work with more than 1 file at a time. best of luck Frank :

Just a guess! You don't have a limitation on virtual memory (pagefile) do you? Do yourself a favor BACKUP!

Thanks for the advice everyone. I'm still not sure though. According to the website you provided, XP "As a rule of thumb, we recommend at least 64 megabytes of main memory for basic AutoCAD operations, 128 megabytes for more sophisticated drawings, and 12 megabytes for using the Mechanical Desktop..." So that's 204 MB they recommend in total. I have 2GB. But I think they're assuming the average AutoCAD user works with much simpler drawings than I am - like simple 2D blueprints. As I said, the file I'm working with is 100MB. It's a 3D model of a landscape and three buildings with details up to the balcony railings and the leaves on the trees. I've got textures on almost everything and high resolution shading. Is it possible that a drawing like this needs more than 2GB of memory?

"Is it possible that a drawing like this needs more than 2GB of memory?" It shouldn't cause a problem if it does, as long as you haven't disabled or limited virtual memory. Also, as long as you have enough free space on the hard drive for the page file to expand. Do yourself a favor BACKUP!