Tuesday, January 01, 2008

Managing RAM Memory in AutoCAD MEP

A friend of mine (Tony Isenhoff of Eppstein Uhen) and I were discussing how RAM is utilized by Autodesk applications. As you work in your application, RAM is used, and in many cases is not returned to the OS when it's no longer needed. The problem arises when you start to reach the 2 GIG limit for a Process in 32 Bit Windows or you simply start to run low on memory when you are working on large projects.

But if you simply Minimize the application window, wait a second or two then Maximize your application, the RAM is given back and you can continue working.

Tony confirmed this in Revit by opening one of their larger projects using Revit Architecture, and opened 3-4 views, and watched the memory usage go up, then minimized. Below are the results:

Before minimize:

After minimize:

I also confirmed this in Revit MEP and AutoCAD MEP.

So when working in AutoCAD MEP and you get a message that you're running low on memory, try minimizing the application window!

We always knew that having multiple views open can also affect performance, but we were pretty surprised at actually how much RAM is used.

One view open: 784,380 k
Two views open: 817,520 k
Three views open: 847,220 k
Four views open: 872,896 k

So closing views that are not being used is also very important.


  1. Thats a great tip. It helped me alot in our MEP coordination.

    Thank you,
    MEP Modeler
    Manila, Philippines

  2. AnonymousMay 05, 2009

    Great little tip to know.

    Would be better if someone, somewhere had a proper comprehensive look at AutoCAD and resource usage. I have to rely on google to get titbits like this.

  3. While trying to open Auto Cad file more than 100mp size showing not enough memory to open this file. Why this? I am using 4GB of RAM and 1GB display Please help me