Important: Please read the Qt Code of Conduct -

Adding single QML Text item adds 21s to start-up time!

  • We are struggling with very long start-up time of our application.

    Some details:
    Treq M4 screen, 624 MHz ARM
    Windows CE 6.0 R3
    Qt 5.4 shared libraries
    No OpenGL ES 2 support so using 2D Renderer

    In order to find the bottleneck we made some simple test applications. Here are the descriptions with measured start-up times:

    Qt Widget application with single label: < 3 s
    QQuickView with one Rectangle: < 3s
    QQuickView with one Text item: ~24 s
    QQuickView with two Text items: ~24s

    I am thinking that the issue is not the loading of the dlls. Because Widget application and Qt Quick Rectangle application loads fast enough.
    The issue is not parsing QML. These sample QML files are just a few lines long.
    It is not the instantiation of the Text item. Because adding a second Text item is instant.

    What is going on?



  • It has been suggested that the issue is related to the font system initialization.

    Could it be that our Qt build is not configured to use the right font engine. Maybe the font engine is not efficient in combination with the 2D Renderer? The Qt Widgets application works fine, so I am wondering; what is the difference between the Qt Quick and Qt Widgets w.r.t. font rendering? Is there a way to make the font system under Qt Quick work like the font system in Qt Widgets? I don't really know what I am talking about. Please help.

Log in to reply