AutoCAD 2018 using full processor thread with no drawings open

[nrz13]

I'm not sure how long this has going on, but it's something I just happened to notice yesterday and today:

AutoCAD 2018.1.1, with no drawings open, is using a little over a full processor thread (10%-12%) while it should be sitting idle.  It doesn't happen right away, but if it's been sitting idle for a little while (an hour maybe?) then sure enough it ramps up.



My full spec is below, but the i7-8700k has 6 cores, 12 threads, so I haven't noticed a performance hit.  At the same time, I don't want to be burning a processor core all day long and reduce the life of the computer for no good reason.  Interestingly enough, since a fully utilized thread is only 8% of the full processor load, it appears AutoCAD seems to be running a multi-thread process while sitting idle.

Let me know if you've seen this happening and if there's any solution.  Thanks

[john.vellek]

Hi @nrz13,

Here is an article that might apply although it indicates a drawing is open yet idle.

Is there a reason to leave an application open if it is not in use? (I am pretty old school in that regard)

[nrz13]

It does seem that the problem originates with an open drawing, and then persists even after that drawing is closed.  I have been monitoring occasionally today, but have not seen it crop up yet.  I'm still trying to narrow the criteria down a bit.  Obviously, if someone else has had this issue before and already figured it out, that'd make it easy for me.

As for your possible solutions, I've already disabled the onboard graphics.  When I have more time, I'll look into installing updated graphics drivers and the Visual C++.

If AutoCAD still opened in approximately 3 seconds like v. 2012 used to, then I would shut it down every time.  But even on the higher end hardware I have now, it still takes 8 seconds to open.  Seems like a short time until you're wanting to get going on a task, or get a phone call from a client and waiting to open a drawing.

But, as I discovered after posting yesterday, the problem seems to originate from an already open drawing.  So in that case, shutting and re-opening a drawing I'm working in a lot is not an ideal solution.

I'll post back if I find out any more information on what causes it or if the graphics card update or Visual C++ reinstall help.  Doing this makes me nervous, though, because in my experience tweaking with these things is just as likely to mess something up further as it is to fix a problem.

[john.vellek]

Hi @nrz13,

I think I would be a bit hesitant too. Start with the graphics card driver which is easy to roll back. Little steps and then some monitoring.

[nrz13]

That was my plan too – thanks!

[nrz13]

@john.vellek

I sent you a .dwg file to see if there's any testing you can do on your end, just in case this problem is file-dependent.

Thanks

[nrz13]

This just happened again today, different drawing than before, and occurred within 5 minutes of opening the drawing.  Closed it out and CPU usage remains steady at 10%-12%.  I then closed AutoCAD, reopened it with the same drawing, and it's sat idle for over an hour with no issues.  So it appears the problem is program-related and not drawing-related, but I'm still unsure of the specific trigger.

Installing the most current graphics drivers did not help this issue.

[john.vellek]

HI @nrz13,

Thanks for  the update.  Hav e you tried the re-install of the C++ as mentioned in the article I provided earlier?

Please select the Accept as Solution button if my post solves your issue or answers your question.

[nrz13]

Not yet.  I'm afraid to after past problems I've had with messing with those C++ installations and with all the problems I encountered changing the video drivers yesterday.  It will have to wait until I don't have a big deadline hanging over my head before I experiment with something like that again.

In the meantime, I'll continue to monitor to see if I can find a common trigger to reproduce the issue.  Thanks

[nrz13 · Accepted solution]

Installing AutoCAD 2020 seems to have fixed this bug.  I can't tell 100% since it was an intermittent bug, but it hasn't surfaced since the 2020 install.

[nrz13]

I've noticed this problem intermittently in AutoCAD 2022 now.  I'm not sure if it started right away after installing or not; I just happened to have Windows Task Manager open and noticed AutoCAD maxing out a full processor thread even though I had no drawings open and the program minimized.  As before, because it happens intermittently it's hard to pin down any cause(s).

I don't notice any performance problems because of it because I still have 11 other processing threads available for use, but it's certainty generating more heat in my computer case and potentially reducing the longevity of the components inside.

The root cause was never determined before, so I don't expect any solution to this problem at this point.  Just posting here in case others have the same problem.  I don't recall having the issue in the 2020 version, although with it being intermittent and not having Task Manager open all the time, I can't say for sure.

[CADbloke]

I have 2022, 2021 & 2019 installed on the same machine. After numerous attempts to get 2022 to calm down on the CPU hogging, I found the only solution is to abandon 2022 and use 2021. Of course another solution is to abandon Autodesk but that's a whole other topic.

Take a look at what acad.exe is doing SysInternals' ProcMon - it's not pretty. My 2022 installation was spamming the registry. I added entries to address that but it didn't fix it. 

Edit: I spoke too soon, 2020 did it too but it did eventually calm down. I did notice that if a drawing open in AutoCAD is opened by another application as read-only then the CPU seemed to spike in AutoCAD. The drawing is on a network share. Yes, I know Autodesk says don't use network shares but I'm not paid to work around their bugs. 

[CADbloke]

Just some thoughts
- anyone else using Visual Studio (2019 Pro) & have it open when the CPU goes runaway?
- anyone have files open on a network share?

[nrz13]

No, I don't have or use Visual Studio.  We do have a local file share in the office (not a "cloud" share), but I have the same issue on my home computer running files from the computer only.  We're just running vanilla AutoCAD with no plug-ins.