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Forum Update on Monday, May 27th 2025

QML runs animations on Raspberry Pi very slow

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  • S Offline
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    Shine
    wrote on 26 Mar 2021, 11:57 last edited by Shine
    #1

    My QML applications can run in raspberry pie 3 b and raspberry pie 4 b, I find that when I run animation effects will cause the CPU takes up more than 100%, thus cause the program's graphical animation operation very caton, this is obviously not truly effective use of the GPU to draw graphics, so I need to how to operate the QML program in raspberry pie 3 b or raspberries pie on 4 b can make effective use of GPU to draw graphics animation can run smoothly.

    This is my Raspberry Pi CPU running, 'IU' is my QML graphics program.
    Note: The program is attached to X11 to run.
    截屏2021-03-26 19.21.45.png

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      sierdzio
      Moderators
      wrote on 26 Mar 2021, 13:05 last edited by
      #2

      Run your app with EGLFS plugin, not X11, and make sure you are running RPi's OpenGL driver (you can enable it in raspi-config).

      (Z(:^

      A 1 Reply Last reply 24 Apr 2021, 22:07
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      • S sierdzio
        26 Mar 2021, 13:05

        Run your app with EGLFS plugin, not X11, and make sure you are running RPi's OpenGL driver (you can enable it in raspi-config).

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        Aros
        wrote on 24 Apr 2021, 22:07 last edited by
        #3

        @sierdzio Hi. When you say OpenGL driver, do you mean vc4-fkms-v3d? Cause I have a similar issue as the OP. I have a simple QML app which is running smoothly on FullHD on any raspberry, but if I run 4K on Raspi 4, it gets very choppy... Again the app is very simple, just text animations.

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          sierdzio
          Moderators
          wrote on 25 Apr 2021, 06:34 last edited by
          #4

          Yes I mean the vc4.

          Not sure about 4k, I've never tested it on such a big screen.

          (Z(:^

          A 1 Reply Last reply 13 May 2021, 20:40
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          • S sierdzio
            25 Apr 2021, 06:34

            Yes I mean the vc4.

            Not sure about 4k, I've never tested it on such a big screen.

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            Aros
            wrote on 13 May 2021, 20:40 last edited by
            #5

            @sierdzio Seems to me that the problem is mostly apparent for animations that include some transparency interpolation. If the scene just shifts texts back and forth, that doesn't seem to be impacted much. Does that make any sense?

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            • S Offline
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              sierdzio
              Moderators
              wrote on 14 May 2021, 06:17 last edited by
              #6

              Yes, RPi has a weak GPU and OpenGL driver is not optimized very well. What you describe seems consistent with some corner case where optimization is lacking.

              (Z(:^

              A 1 Reply Last reply 17 May 2021, 17:29
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              • S sierdzio
                14 May 2021, 06:17

                Yes, RPi has a weak GPU and OpenGL driver is not optimized very well. What you describe seems consistent with some corner case where optimization is lacking.

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                Aros
                wrote on 17 May 2021, 17:29 last edited by
                #7

                @sierdzio OK thanks for letting me know. At least I know it's not driver related and can optimize the app not use that kind of animation much.

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