Electronics

Electronics

Abnormally slow computation speed

    • Antoine Dupuis
      Subscriber

      Hi !

      I'm trying to simulate the lorentz force on an actuator between two magnets. This is a transient solver simulation.

      My 3D model is ridiculously slow and I don't understand why... Here is what I have done so far:

      • reduced the number of mesh to 500 000
      • Allowed for 4 cores, 90% RAM limit and GPU use in Analysis configuration
      • Set the power management mode of my GPU to “Prefer maximum performance”I have reduced the number meshes to 500 000, which shouldn't be any problMy 2D

      What I notice is that is it very slow (more than 5min) to even get actually started on the simulation (reading file, etc...) despite mesh generation very smooth and nice look when plotting the mesh. Then it start solving where CPU use goes from 15% to around 50-70%, GPU oscillates between 5-50% with peaks close to 100% and the memory usage is over 90%... Then it doesn't even reach time step 0s but crashes before with the following error message:


      "3dtds terminated abnormally"

      My desktop config is: 16GB RAM, SSD 239 GB, GPU NVIDIA Quadro K620, Windows 10, 4 cores CPU

      To explore what could be wrong I have tried a 2D equivalent model with finner mesh with a total of 400 000 meshes, so very close to the 3D model. When solving the 2D model everything goes fine with CPU use of 15-30%,GPU 0-2% and memory usage of 33%.

      Does anyone know what could be the reason for this problem ? any help would be a lot !

      Thanks !

      Antoine

    • GLUO
      Ansys Employee

      Hi Antonie,

      3D projects are harder to be solved than 2D projects with the same mesh count. However, the error message "3dtds terminated abnormally" is not neccessarily related to out of memory or mesh issues. Could you first try solving with all mesh operation disabled, and use the following initial mesh settings if your AEDT is in 2022R2 version or below? 

      Thanks,

      GL

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