AutoCad 2009 Memory/Render problem

Opening a file bigger than about 50MB I end up with AutoCAD using up to 1.2 GB of RAM to start with (ever increasing during work). As I’m using a 32bit version of Windows and hence “only” 3GB of RAM the free Ram level drops to below 1.3GB. This is not good enough for AUTOCAD to render that particular view- it crashes. Reducing the render quality doesn’t help. I also tried to reduce the FG values from 1000 to 200, the photon v. from 10000 to 5000 wouldn’t help.

I once minimized the program which resulted in a drop of the RAM usage to about 400MB. No more problems afterwards but ever since the trick doesn’t work anymore. Now AutoCAD disappears from the Task Manager Process list but the free memory level stays as low as it was.

Same sort of file but just below 50MB no problem. Is there any way to force AutoCAD to free some memory?

Would be great if somebody had an idea.

XP home SP3/ Pentium Core Duo T7500 2.2GHZ/NVIDIA GEFORCE 8600M GT/3GB RAM

Thanks in advance

I work with 50MB+ files everyday. Trust me, I feel your pain. I don't render as much, but I cut sections with the AEC tools in ACA and it puts a similar, albeit shorter, strain on the system resources. To my untrained eye the problem seems to be a huge memory leak, AutoCAD does not release the memory back to the system once it is done with it. If you keep a system resources tracker up, you'll see your memory usage plateau every time you perform a render. The only way I've been able to "work" around this is to try and be as efficient as possible, both in my modelling, and my command usage. Triple check everything is right before a render so you do not have to repeat it, exacerbating the problem further. Also try to freeze any objects which are not immediately viewable in the shot, even if out of frame the render engine will still shoot rays to them. Beyond this all I can suggest is a strong keyboard and a large bottle of ibuprofen. (But hey, long regens/commands and system crashes are what let me bounce around here so much *shrug* )

Thanks MaxwellEdison, now I know at least I’m not alone and the memory issue seems to be a recognized AutoCAD feature. Right after posting my question I found a link to an Autodesk site where they offered a hot fix for exactly that problem. My joy was only short term though as it turned out that my version of AutoCAD already contains that hot fix. They seem to know that they are having problems but obviously either are unable or just not willing to resolving them.

Cheers

you are not alone, I can only do one big render per session with my install of 09, any more than that and I risk it crashing. This is even with small files, but very in depth renders.

Cadfisch: How much RAM (max) can you install on your motherboard? If you can get 4MB then despite using a 32-bit version and running on XP (Pro or other?) you could edit your boot.ini file to run utilizing what is commonly referred to as the 3/GB switch. This will give AutoCAD almost 1 GB extra RAM to work with. It might help.

What other steps have you taken to maximize AutoCAD's performance?

You may also have to look at swapping out your graphics card.

Same here...was working on a 35Mb enterior scene,what a nightmare.(Core2Duo T7250 2.0Ghz 2Gb ram)

Also try to freeze any objects which are not immediately viewable in the shot, even if out of frame the render engine will still shoot rays to them.

Very very useful info! I used to delete the objects wich are not visible in the scene,but if this work than it would be a time saver.

Cheers.

Thanks guys for all the answers and thanks a lot for your advice ReMark. I will definitely try this ‘3GB switch’. I can top up to 4GB and as soon as I’m free (weekend) I’ll go buy a new chip. I’m on a laptop so I can’t swap the graphics card. The one that I’m using has its own 512MB Memory so I don’t see a problem on this side. I’m running XP home but just read on a Microsoft site that all versions of XP support that feature.

I don’t seem to be able to really ‘edit’ my boot.ini file unless my approach is wrong: msconfig/boot.ini?

But I have an “Advanced” button there which offers amongst others to tick /MAXMEM, is it that? The value to put in will be in MB, means 3072?

Other than that I’m not aware of any steps that I could take to maximize AutoCAD’s performance. If you could give me a hint on that one would be appreciated.

Re. MaxwellEdison's otherwise probably useful suggestion to freeze everything out of sight - unfortunately in this case there is absolutely nothing that I could freeze for the renderings.

Cheers

The boot.ini file can be accessed via Start > Run > msconfig (as you stated). However, before you start I would caution you to make a backup copy of the file and keep it on a flash drive (as insurance). Next, carefully edit the boot.ini file as suggested by AutoDesk and before saving it check over what you've typed not once, not twice but three times...character for character. A boot.ini file that is incorrect could make your system inoperable. Finally, some hardware, like graphics cards, do not play well with the 3/GB switch activated. If you experience any weird problems (like AutoCAD crashes) then revert back to the original boot.ini file.

I am currently running AutoCAD 2009 on my system under WinXP Pro with 4GB RAM utilizing the 3/GB switch and have not experienced any problems what-so-ever.

Thanks ReMark

In the msconfig window I cannot edit boot.ini probably because I’m on the ‘Home’ version. However I found it in the System properties/advanced section. There I can open it with an editor. It looks as follows:

[boot loader]

timeout=30

default=multi(0)disk(0)rdisk(0)partition(1)\WINDOWS

[operating systems]

multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Microsoft Windows XP dition familiale" /noexecute=optin /fastdetect

An example that I found for a changed boot.ini (I just don’t find it anymore in the AutoCad Help) looks as follows

multi(0)disk(0)rdisk(0)partition(2)\WINDOWS="Microsoft Windows XP Professional" /fastdetect

multi(0)disk(0)rdisk(0)partition(2)\WINDOWS="Microsoft Windows XP Professional 3GB" /3GB /fastdetect

What worries me is the part (in my boot.ini) /noexecute=option/ do I have to add the 3GB command after or before that? And do I have to put it as in the example twice?

Cheers

Take a look at this:

http://vlaurie.com/computers2/Articles/bootini.htm

Then take a look at this:

http://www.vfxpedia.com/index.php?title=FAQ/3GB_Switch

Finally, from AutoDesk:

http://usa.autodesk.com/adsk/servlet/ps/item?siteID=123112&id=11857241&linkID=9240617

ReMark,

thanks for the links, but – thank you very very much for your advice regarding the /3GB switch!! I’m living in another world now! This morning I was sitting in front of the screen with a beating heart watching a rendering to proceed that never ever went through without crashing AutoCAD and when the last black squares got eaten up I just couldn’t believe it. I’ve been working the whole day without one crash but in the afternoon I dug out a 70MB file that so far could only be rendered in three steps (put together in Photoshop later) and again, no problem! I could probably still be looking much younger if I had known that before.

Thanks again and thanks to everybody for joining in with advises.

Cheers

You're entirely welcomed, Cadfisch. I'm glad to hear that at least for you the 3/GB switch worked the way it was intended. One question: When you boot up now is the option to work with the 3/GB switch first or second?

Hi ReMark,

I’m including a copy of my boot.ini. At the moment the /3GB switch option is second but now that I know it works fine I will put it first and change the timeout to 15 seconds so I don’t have to manually select it every time I boot. I added the “USERVA=3030” because I read that some people had problems when selecting /3GB/3GB. Reducing the 3GB to 3030 or even to 2090 seems to be safer.

One important issue – it is now obvious that XP Home supports the 3GB switch.

[boot loader]

timeout=30

default=multi(0)disk(0)rdisk(0)partition(1)\WINDOWS

[operating systems]

multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Microsoft Windows XP dition familiale" /noexecute=optin /fastdetect

multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Microsoft Windows XP dition familiale 3GB" /noexecute=optin /fastdetect /3GB /USERVA=3030

Thanks for the update Cadfisch. I was going to suggest moving the 3/GB switch enabler to the forefront just as you have done. I was not aware of the USERVA=3030 option and will have to read up on it although I am having no problems running without it. Thanks again.

Auto cad 2009 show some Error msg:

"AutoCAD is running out of system memory" please solve my problem

rajkishor_sharma:

First. Welcome to CADTutor.

Second. It is not a good practice to add your question to the end of another forum member's thread. You should have posted it as a new question in the proper forum.

Third. What are the specs on your computer? How much physical RAM is on the motherboard? What OS are you running? What were you attempting to do when the message appeared? Have you loaded the service pack for 2009?

CadFisch,

I have'nt been on the forum for awhile so this might be a little late but there is a free utility called RamDef. It monitors your ram use and defrags and releases ram while you work. You can get it on "majorgeeks.com". hope it helps.

Heavysan,

Thanks for the info. I will have a look at it as soon as I can. I’m not too confident though, because when I had those problems I also tried some memory tools without success. But as it works for you, RamDef seems to be a better tool. For me the 3GB switch is the bailout so far and it works with Vista too.