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Ansys Products

Discuss installation & licensing of our Ansys Teaching and Research products.

Fluent doesn’t use GPU acceleration

    • sophie.nicoud
      Subscriber

      Always this message in the Fluent console :

      "Software rasterizer found, hardware acceleration will be disabled...."

      I understand it's mean I can't run 3D simulation. 

      What's the solution, please ?

      My configuration :

      Linux machine ubuntu 22 Nvidia RTX4000

      GPU and OS matched the requirements

      Information in the console of Fluent :

      CPU/Memory Usage:
      ---------------------------------------------------------------------------------------
                          | CPU                                  | System Mem (GB)                  
      Hostname            | Sock x Core x HT  Clock (MHz) Load   | Total        Available  
      ---------------------------------------------------------------------------------------
      xyz| 2 x 36 x 2        0           6.66   | 1007.38      995.638    
      ---------------------------------------------------------------------------------------
      Total               | 144               -           -      | 1007.38      995.638    
      ---------------------------------------------------------------------------------------


      CUDA visible GPUs on xyz
        CUDA runtime version 6000
        Driver version 12040
        Number of GPUs 1
          0. NVIDIA RTX 4000 Ada Generation (*)
             48 SMs
             2.175 GHz
             21.1253 GBytes

      Many thanks

    • randyk
      Ansys Employee

      Hi sophie.nicoud,

      I am assuming you are running with a remote desktop - such as VNC.

      If that is accurate, please install and configure VirtualGL to do server side rendering.

      1. Confirm that VirtualGL rendering is active
      If you set the VGL_LOGO environment variable before starting an application, a small logo reading "VGL" will be shown in the bottom-right corner of any OpenGL scene that is rendered through VirtualGL in that application:
       
      $ VGL_LOGO=1 vglrun glxgears
       
      If the application runs but the logo does not appear, it means VirtualGL has failed to take effect and the application has probably fallen back to software rendering.

      2. Run the Ansys application 

      $ vglrun /path/v251/fluent/bin/fluent

      Please let me know if this helps.

      thanks
      Randy

    • sophie.nicoud
      Subscriber

      Hi Randy,

      Step 1 is OK. I got the logo VGL

      Step 2 it's same, I got teh message ""Software rasterizer found, hardware acceleration will be disabled...." in fluent console

      Thanks for your reply

      Sophie

    • randyk
      Ansys Employee

      Hi Sophie,

      Can you please share the output from:
      $  vglrun glxinfo | grep -i opengl

      thanks
      Randy

    • sophie.nicoud
      Subscriber

      Hi,

      # vglrun glxinfo | grep -i opengl
      OpenGL vendor string: Mesa
      OpenGL renderer string: llvmpipe (LLVM 15.0.7, 256 bits)
      OpenGL core profile version string: 4.5 (Core Profile) Mesa 23.2.1-1ubuntu3.1~22.04.3
      OpenGL core profile shading language version string: 4.50
      OpenGL core profile context flags: (none)
      OpenGL core profile profile mask: core profile
      OpenGL core profile extensions:

      Thanks a lot

      Sophie

    • randyk
      Ansys Employee

      llvmpipe is software rendering. The llvmpipe driver is used when the hardware graphics driver is not available or if there’s a problem with the hardware. 
      You will need to resolve the driver issue.
      Make sure you have the NVIDIA driver installed, xorg.conf configured, BIOS configured, etc…
      I suggest a web search with keywords: llvmpipe instead nvidia gpu

    • sophie.nicoud
      Subscriber

      Hi Rand,

      Apologize, it was a no configuration of BIOS.

      I set "Secure boot" in the BIOS at no and it's OK (I hope)

      Fluent run without error with this command : vglrun /path/fluent

      xrdp or TurboVNC are fine to connect to the server if I use vglrun

      Thank a lot for your help

      Best regards

      Sophie

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