4 Replies Latest reply on Mar 8, 2014 4:33 PM by Jared Conway

    Tweaking and limiting RAM usage of Simulation?

    John Doe

      Hello,  Ive read in several areas that since I have 32GB of RAM and a page file of 40GB+ on a SSD, I should limit Simulation's RAM limit to just use 32GB of RAM and not use any page file. Thoughts?  Also, Ive always read about tweaking and configuraing Simulation correctly to run and work better. Where can I search for tweaks so I can ask my collegues what exactly they use and then turn on/off several settings to make it even faster?  Thank you

        • Re: Tweaking and limiting RAM usage of Simulation?
          Eric Irwin

          You would have to be running a fairly complex simulation to use all of your 32GB of RAM.  I generally find that if it starts to use something like 7-9GB of RAM, then it is starting to fail.  Of course your simulations may be bigger than mine.  Unless you are analyzing some really big stuff, the 32GB of RAM with the 40GB page file should be fine.  You can watch the memory usage as it is being solved, but I think you have to select the "See More" button or whatever it is called.

           

          Remember that other things on your computer are also using RAM, so you don't have the full 32GB to use in your simulation.

           

          One quick tip for making it run smoother and getting better accuracy.  In the feature tree, right click on the title of your Study and select Properties.  Then pick the Adaptive tab and use "h-adaptive", target accuracy of 98%, max loops of 5, and select Mesh Coarsening.  Also on the Options tab select Automatic for the Solver.

          • Re: Tweaking and limiting RAM usage of Simulation?
            Jared Conway

            if you do this, windows will not be stable. it doesnt' behave well with no page file. you're welcome to try but i think your gains will be minimal and your stability will go down significantly.

             

            what is the actual problem that you're running into with your simulations?

            • Re: Tweaking and limiting RAM usage of Simulation?
              John Doe

              We are simulating several simulations and we hit the 32GB RAM (task manager shows all the RAM used up but the simulator) and paging begins to put a 40GB+ page file on a SSD. I was thinking of getting a separate HDD (or small SSD) just for paging.

                • Re: Tweaking and limiting RAM usage of Simulation?
                  Jared Conway

                  what type of simulation? has the setup been optimized? we do a fair bit of analysis consulting here at Hawk Ridge Systems. We have had a lot of complicated problems brought to us that we've brought down to a reasonable size through thoughtful setup considerations. my experience is that once you get beyond a few milion DOF, you start running into problems where you're waiting for results more than you're able to use them to make decisions.