AutoCAD Performance

What can you do to AutoCAD, to improve performance?

Don’t open any drawings!

Let’s face it, as soon as you open a drawing AutoCAD runs slightly slower… the more drawings you open the slower the performance…

OK, not a good solution.

Here’s some suggestions, you will find these on a number of web sites, I’ll repeat them here, but have to say, I rarely utilise any of the following for improving the performance of AutoCAD, but for the record…

Reduce the amount of information you are working with. If you can simplify the drawing you are working with you may be able to avoid those annoying “out of memory” errors. For example, if you are hatching large areas, try breaking it down into smaller sections. If you have images and/or xrefs in the drawing, try unloading the ones you do not need at the moment. If there is a lot of TrueType® based text on the screen, try replacing it with a SHX font instead. If there are multiple drawings loaded, try closing the ones you are not working with. There are many other methods you can use within the program to reduce the amount of memory being used.

Commands and System Variables that Improve Performance

Following is a list of the commands and system variables in AutoCAD/AutoCAD LT that you can use to improve drawing performance:

• PURGE command. This command clears unused layers, blocks, linetypes, dimension styles, text styles, and multiline definitions from the drawing.
• CONVERT command. This command converts any old-style polylines and hatches to the optimized format, and can possibly reduce drawing size and memory usage.
• INDEXCTL system variable. INDEXCTL controls whether layer and spatial indexes are created and saved in drawing files. Set it to 1, 2, or 3 for improved performance when doing an xref demand load of the current drawing. However, setting INDEXCTL to any value other than 0 increases the amount of time required to save the drawing and increases its size. Note: By default, INDEXCTL is set to 0 when you create a new drawing.
• FILLMODE system variable. FILLMODE specifies whether multilines, traces, solids, all hatches (including solid-fill) and wide polylines are filled in. Setting this system variable to Off decreases regeneration time.
• Unload xrefs and images. Unload xrefs and images that are not needed in a drawing session to decrease memory usage and regeneration times.
• Quick Text Mode (QTEXT). When Quick Text mode is on, only a frame defining the text is displayed, which can improve drawing performance. Note that when Quick Text is on, the text frame, but not the text, is plotted.
• Layer control. Freezing or hiding layers that are not needed in a drawing session speeds the selection process, regenerations, zooming, and panning.
• Partial load (not available in AutoCAD LT). Using the partial load feature allows you to load only parts of the drawing you want instead of the entire drawing.

So, does anyone use any of the above?… besides PURGE of course, which we all run regularly (don’t we?) and the occasional AUDIT… so what about…

Dynamic Input

You could disable this, even on a high spec computer you will see a significant hit on the CPU with Dynamic Input enabled, but still a useful facility… and let’s face it – if the CPU is not taking a significant hit, then you are obviously not working hard enough!

Please also note: The above proves that I do in fact have the ability to draw a line in AutoCAD… and not just any line I might add… it is a 45 degree line at 313.4935 units long!

Visual Effect Settings

This is one to look at, just to disable the annoying Selection Preview all together, particularly if you work with large external reference files…

My preference is to disable it all together, but their are selection options if you prefer…

Select “Advanced Options”…

 

Summary

So what do we learn from all of that…

Well, if you are unfortunate enough to be restricted to an under-specified computer that is struggling with running AutoCAD, then some of the above may help. However, in the majority of cases, if you are in the business of driving CAD, then you most likely have the luxury of a machine that is more than up to the task.

The bottom line is, we don’t just drive CAD. We run multiple applications, all of the time and the hardware that we use needs to be up to the task of driving these multiple applications.

My suggestions:

1. Know exactly what you have running on your machine.
2. Know the processes/services that are running on your machine.
3. Armed with that information… you can now disable those applications/processes/services that you don’t need all of the time… you know the one’s… the Instant Messengers, background apps for snagging images and videos, etc. etc.
4. You obviously need these disabled applications at some time, so setup some simple scripts to switch them back on when you need them. I’ll follow up with some examples later.

Comments

[Earl Kubaskie]

Well done, John. Sometimes performance is almost voodoo, and the P4 with 2G RAM across the hall will do as well as my i7 with 12G.

I think I'll try hanging a chicken foot from the "cup holder".

[leon]

very good advice