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  1. Qt
  2. QTBUG-50496

Unreasonable CPU load when using QOpenGLFramebufferObject

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    Details

    • Type: Bug
    • Status: Closed
    • Priority: P2: Important
    • Resolution: Done
    • Affects Version/s: 5.6.0 Alpha
    • Fix Version/s: 5.6.0 RC
    • Component/s: GUI: OpenGL
    • Labels:
      None
    • Commits:
      fd6cf5c875d794d23e513c8e7d6ebabc91dae790

      Description

      Run an application that renders into an FBO and thus runs QOpenGLFramebufferObject::bind() on every frame, and watch the CPU usage.

      With NVIDIA drivers the CPU usage for drawing a triangle into an FBO and texturing a cube with the texture used as the color attachment for that FBO gives 19-21% CPU usage on Windows.

      A big part of this is the glCheckFramebufferStatus call in bind(). Removing the call results in 0.8-1% for the same application.

        Attachments

        For Gerrit Dashboard: QTBUG-50496
        # Subject Branch Project Status CR V

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            Assignee:
            lagocs Laszlo Agocs
            Reporter:
            lagocs Laszlo Agocs
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              Dates

              Created:
              Updated:
              Resolved:

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