Discussion about AutoCAD LT performance/slowness.

[glaucoP4TC5]

Good morning, everyone!

I'd like to start a discussion about AutoCAD LT performance/slowness. I've been a furniture designer for 20 years, started with AutoCAD R14, and now I'm using the 2025 version (LT). I've been through it all, from Pentium 3 to the Core i7s of today, from Windows 98 to Windows 11, and from 32MB of RAM to 32GB. Projects used to be made with just a handful of lines, but today they're getting more and more complex, filled with details like screws, fittings, and intricate hatches.

I get that things evolve, but I've never felt so much like I'm wasting time waiting for AutoCAD to open a block or hatch an area. Creating a viewport, for instance, now takes so long that I could go grab a coffee and come back.

I've gone through every tutorial, tip, and video out there on how to speed up AutoCAD and lighten the drawings. I’ve got one of the best PCs for this kind of work (Dell Precision 3680), yet when I create a viewport, it still takes 15 to 20 seconds. Meanwhile, when I check the Task Manager, I see most of my hardware is just idling, barely using 10% of its capacity!

So here’s my big question: am I reaching the limit of what AutoCAD can do? Or have I been working the wrong way for years? From what I’ve learned (thanks to ChatGPT), AutoCAD LT only uses one core of the processor (I’m still trying to find more reliable sources to confirm this).

I'd love to hear your experiences. Does anyone else deal with this? Or maybe someone will tell me: "Glauco, you’re crazy, 10 to 20 seconds per viewport is nothing, get over it!"... I’m okay with that, as long as it comes with a good laugh! 😂

Thanks in advance for your help!

[pendean]

@glaucoP4TC5 No such issues here in an office full of users of AutoCAD and LT 2025 in Windows 10Pro/11Pro, but we are a commercial office with a secure Windows File Server and a robust network.

Where do you store your DWG files? And how are you linked to that source?

Have you installed the 2025.1 Update yet? ABOUT command in your AutoCAD will confirm what you have installed. If not, get it from your Autodesk Account Page here https://manage.autodesk.com/cep/#products-services/updates
Restart your PC afterwards.

If that did not help... Set GFXDX12 variable to 0 (that's a zero) then restart AutoCAD/LT2025: reverting to DirectX11 fixes similar problems for most users.

Also consider turning off LINESMOOTHING and LINEFADING variables.

If still no relief then start GRAPHICSCONFIG command and change the 2D Display Settings pulldown from "advanced mode" to one of the other choices.

If none of the above helped, start here with this longer list
https://www.autodesk.com/support/technical/article/caas/sfdcarticles/sfdcarticles/Graphics-system-ca... 

HTH

[jskalaXDDX5]

Nothing like that with much less of a computer than you have and a lot of stuff going on in the background...

Obvious question maybe, but how far from 0,0 are you working?  

Maybe also consider CUI macros...especially good IMO for hatches...Autocad is usually pretty efficient talking to itself...

[glaucoP4TC5]

Thank you all for the responses!

@pendean, thanks for the suggestions. Even though I followed several tutorials, I haven't noticed significant improvements yet.

@jskalaXDDX5, thanks as well! Yes, I'm working close to the 0,0 point. This is where I place the project information stamp, so we always work very close to it.

I’m also curious about the CUI macros. Could you explain a bit more about how they work?

Once again, thank you all!

[jskalaXDDX5]

Great video on CUI stuff here:

https://www.youtube.com/watch?v=OGegAVVT8t0

In terms of practical for hatches, this macro repeats, picks pattern, Layer, pauses for user input, etc.

*^C^C-HATCH;PROPERTIES;ANSI31;1.0000;0;LAYER;3;\;

This does the same but adds draw order.

*^C^C-HATCH;PROPERTIES;ANSI37;9.0000;0;LAYER;4;\;DRAWORDER;\;BACK

Symbols replace some controls, ^C = Escape.  There are only a handful of symbols so it’s not too bad a learning curve and is a great way (imo) to use a lot more of the functionality available with a lot less effort.

[moneumiko]

When I was still on Windows, there was a moment once (like 2 years ago) when all of a sudden my AutoCAD would become super slow for no apparent reason. It was incredibly slow, and I knew it must have been something, some setting etc. And finally I found the culprit! It was the BLOCKMRULIST System Variable - it's the number of most recently used blocks displayed in the Recent tab of the Blocks palette, so after I changed it to 0 the problem was gone!

BTW when talking about AutoCAD performance, generally I always thought it was a bit too slow, whatever PC configuration I had (even on a i9 gaming laptop). After I switched to Mac, I was amazed how incredibly fast AutoCAD for Mac is!! That's why I keep working on the Mac version even though I was fully prepared to work on the Windows one through Parallels (I do use it from time to time to run a lisp routine etc.). Saying this just as a side note 🙂 not to talk anyone into switching because, unfortunately the Mac version is still devoid of some features.

[pendean]

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@moneumiko wrote:

...And finally I found the culprit! It was the BLOCKMRULIST System Variable - it's the number of most recently used blocks displayed in the Recent tab of the Blocks palette, so after I changed it to 0 the problem was gone!...

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Excellent tip: thanks for sharing.

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@moneumiko wrote:

...I was amazed how incredibly fast AutoCAD for Mac is!!...

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Indeed it is: that is the benefit of being forced to rewrite to core code of the program (as are the re-writes for WEB/MOBILE), something Autodesk dreads trying to do for Windows nd avoids it like the plague 😐

[moneumiko]

Yeah, unless Microsoft will make those new ARM processors so good that people will start prefer them and move away from the old architecture based devices. Then Autodesk will have to rewrite the code even for Windows..

[MichaelGibson5012]

Also check that windows is using the graphics card and not the motherboard graphics for autocad LT you can check in the display / graphics then add the acadlt.exe to the list and select the graphics card you want it to use.

[RSomppi]

You should make a comparison with another computer using the same file. Sharing the file here to let others examine it might reveal issues that you don't know you have.