26 Replies Latest reply on Apr 2, 2018 12:08 PM by Ryan Dark

    Solidworks locks up during simulation.

    Josh Barnett

      Good afternoon all,


      First post since joining, so let me introduce myself. My name is Josh and I work for an Engineering Firm in South Florida. I am a novice/intermediate solidworks user, I took a class in college back in 2012, and also have a semester's worth of ANSYS experience.

      Nice to meet you all.


      Running SW2018 w/ professional simulation. 3.4ghz i7 but only 8gb ram(*for now)

      My problem is, I am running a simulation of wind pressure around a large generator enclosure(~230+ parts), I have spent a few hours today on this new model, from fixing everything from interference issues, meshing, etc.

      I am now trying to run the analysis, but as soon as I click the button to run it, a few minutes pass, and the files(.CWR? and .NOD?) update in the folder then after about 5 min the software locks up, and windows explorer asks me if i want to wait or close the program. I click wait, and the NOD file updates. I am now about 30 min into staring at a slightly grayed out screen.


      But I do not see a analysis progress bar or anything. Can someone point me in the right direction?


      Let me know if this is unclear...or more information is needed.


      Thanks for the help in advance!!

        • Re: Solidworks locks up during simulation.
          Ryan Dark

          Hi Josh,

          Windows is will give you this message after a program has not responded to inputs for 3 seconds.  It is not a good indicator of whether the solver is still working for you or not.  You would probably want to go into the Windows Task Manager and check the 'Performance' tab for CPU usage on the STAR.EXE (the solver process itself).  I expect that if you have your CPU setup with default settings you would have 4-cores split into 8-logical processors which would mean STAR.EXE would max out at around 12-13%.  If this is where its CPU usage is then the solver is running and you should grab lunch, get a coffee, or sleep and just leave it alone.


          However, if the CPU usage on STAR.EXE is 0-5% I might expect there is a bottleneck somewhere else causing a massive slowdown.  The likely source would be the RAM since there is not a ton of it in this machine.  If the Windows Task Manager is reporting your total RAM usage around 6 GB then you ran out.  The solve time just increased 100x.  If that's the case you would want to close other RAM using programs and/or simplify your mesh so it uses less RAM for a short term solution.  For a long term solution, get more RAM.  You should put in enough that you don't run out (or even get close).

            • Re: Solidworks locks up during simulation.
              Josh Barnett

              Ok, so I monitored the memory usage, the steep climb is during the meshing, the sudden drop to flat line is when it finished meshing.

              It flat lined for a little while until I closed it (red circle).



              I don't see the star.exe under processes, so I'm assuming it never starts the analysis. I also tried the lightweight option with no luck.

                • Re: Solidworks locks up during simulation.
                  Ryan Dark

                  You definitely have something going on with the solver then.  I might not expect the RAM usage to necessarily changes a great deal once the mesh is complete and the solver starts crunching.  In later versions the STAR.EXE seems to be folded into the SLDWORKS.EXE.  Did you look at the CPU usage of SLDWORKS.EXE while this was going on?  If you can post the file set up on this forum (or send it to me directly) it might be worth running the study as-is on another machine just to see if it is specific to your machine or the study setup itself.

                    • Re: Solidworks locks up during simulation.
                      Josh Barnett

                      Thank you for the help!


                      Below is a drop box link to the file,



                      Let me know if you have any questions about it, do you have a direct way to communicate?

                        • Re: Solidworks locks up during simulation.
                          Ryan Dark


                          I meshed your study which only took a few minutes.  Now it is running the solver and is pretty far along but it is taking a great deal of RAM as it goes:



                          After 5 minutes it is already using 11.5 GB of RAM.  So, if you are rocking only 8 GB in your entire machine then you don't have enough for this.  This would be due largely to the fact that you have set the global mesh element size to the finest setting on the slider which is sending your element count through the roof.  You will need to cut down on this drastically if you wish to run this in any way on your current hardware.



                          The alternative is to get more RAM in this machine.  I have 32 GB in the one I am using right now.

                  • Re: Solidworks locks up during simulation.
                    Dan Golthing

                    FYI, SolidWorks locks up during SolidWorks...


                    With Flow, run times can be insane.  Often would just leave things overnight and hope for the best the next morning.

                    • Re: Solidworks locks up during simulation.
                      Sebastyon Champion

                      have you tried loading your assembly as a lightweight assembly, this could make a BIG difference.