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    AutoCAD 2013/2014 DWG Format

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    Member
    Posts: 3
    Registered: ‎09-20-2012

    AutoCAD becomes unusably slow with seemingly simple model

    1521 Views, 5 Replies
    09-20-2012 10:12 PM

    I have a rather simple file containing some basic geometric shapes (more precisely, guides to be used by a laser cutter to cut out the pieces for a board game). I've built the shapes using a collection of parametric dimensions and other constraints. As I've worked on the file, AC2013 has gotten to the point where certain basic actions are nearly impossible because of freezes and stalls.

     

    The file is attached.

     

    To repeat the problem I'm seeing, select the shapes in the top half of the document and try to drag them (or use the move command) to reposition them. On two machines I've used, AC stalls for over a minute once I try to move those shapes, freezing completely. Eventually it begins responding again, but it may stall multiple times depending on how I drag the shapes.

     

    I'm using the educational version of AC2013 with SP1.1 installed, running in 64-bit Windows 7. My main machine is a quad-core i7 with 16GB of RAM.

     

    Disclaimer: I'm new to AutoCAD and I'm guessing at how to do things, so if I'm doing something fundamentally wrong that is confusing AC, please let me know. Thanks.

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    New Member
    Posts: 1
    Registered: ‎09-21-2012

    Re: AutoCAD becomes unusably slow with seemingly simple model

    09-21-2012 04:31 AM in reply to: ethan.trewhitt

    Autodesk have a really crappy GPU-support and it might be that, that gives you the bad performance.

    I have a Radeon HD7850 GFX-card and a REALLY fast new pc, but Acad still runs bad, even if I only have one line drawn.

     

    What GFX-card do you have?

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    Active Contributor
    LaserGuy
    Posts: 37
    Registered: ‎03-24-2011

    Re: AutoCAD becomes unusably slow with seemingly simple model

    09-21-2012 05:20 AM in reply to: ethan.trewhitt

     

    You have 949 constraints in that drawing. Depending on how powerful your workstation is you'll will want to split into multiple drawings to reduce that to a manageable number. I usually try to keep in less than 1500. I have drawings less than a 1Mb that can bring AutoCAD to its knees. Also use polylines instead of coincident constraints at each vertex. See attached example

    Dell T7500
    x5690 Xeon 3.46/3.73GHz
    24Gb, SSDs, Quadro, Win7 x64
    AutoCAD Mechanical 2014
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    Active Member
    Posts: 7
    Registered: ‎01-18-2005

    Re: AutoCAD becomes unusably slow with seemingly simple model

    09-21-2012 07:30 AM in reply to: LaserGuy

    You do not need any constraints at all to draw something like this. Make sure that the Infer Constraints (left end of the status bar) button is turned off when you start drawing. Regular drawing aids like OSNAP, Polar tracking, etc. are all you need.

    Jeff

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    Member
    Posts: 3
    Registered: ‎09-20-2012

    Re: AutoCAD becomes unusably slow with seemingly simple model

    09-21-2012 07:57 AM in reply to: ethan.trewhitt

    ThomasT1976 wrote:
    What GFX-card do you have?

     

    I'm using a Radeon 4890.

     


    LaserGuy said:
    You have 949 constraints in that drawing. Depending on how powerful your workstation is you'll will want to split into multiple drawings to reduce that to a manageable number. I usually try to keep in less than 1500. I have drawings less than a 1Mb that can bring AutoCAD to its knees. Also use polylines instead of coincident constraints at each vertex. See attached example

     

    Thanks for that. I will learn how to use polylines and see if that does the trick. 

     


    laurich said:
    You do not need any constraints at all to draw something like this. Make sure that the Infer Constraints (left end of the status bar) button is turned off when you start drawing. Regular drawing aids like OSNAP, Polar tracking, etc. are all you need.

     

    I can probably build this all without constraints, but having come from the Inventor world where constraints are used everywhere, they seemed like the easiest way to ensure that certain distances matched my requirements. At the same time, I wanted to be able to change certain dimensions and have everything update to match, and constraints seemed like a good way to make that happen.

     

    It seems to me that the problem with contraints is that it's an all-or-nothing proposition. If you apply one constraint to an object, you have to fully constrain it, otherwise you'll end up with a shape that's constantly changing in unpredictable ways.

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    Active Member
    Posts: 7
    Registered: ‎01-18-2005

    Re: AutoCAD becomes unusably slow with seemingly simple model

    09-21-2012 08:44 AM in reply to: ethan.trewhitt

    "I can probably build this all without constraints, but having come from the Inventor world where constraints are used everywhere, they seemed like the easiest way to ensure that certain distances matched my requirements."

     

    I see where you are coming from, but with simple shapes like this, the other drawing aids in AutoCAD are more than adequate. Constraints are really only necessary if you are going to be making continuous modifications to the design and want to lock down certain relationships between features.

     

    IMHO, it's overkill on a drawing like this.

    Jeff

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