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Qt Performance : QT Widget Application vs WPF

  • Hi All,

    I was trying to evaluate QT vs WPF in terms of Memory , Performance , Window HAndles, User objects, GDI and so on..
    So built 2 identical looking controls in WPF and QT with all values harcoded.
    BAsically a usercontrol - which is "QFrame holding 3 Labels with text, 3 labels with Images, 3 combo box, "
    and created the usercontrol in a loop of 100, 200 ,1000 , 10000 and so on... with the button click on the main window,
    The code in QT is as follows...

    void MainWindow::on_pushButton_clicked()
    QElapsedTimer myTimer;

    for(int i=0;i<100;i++)
    QListWidgetItem *item=new QListWidgetItem(ui->listWidget);
    UserControl *row=new UserControl (0);
     ui->timeLabel->setText( QString::number(myTimer.elapsed())+ " ms");


    On Measuring the performance, with the above code in QT (vs WPF with very identical code in WPF)
    -> First of all in QT,I could notice a lot difference in performance measure between the debug build vs release build of QT( say if release build take 1.3 sec to create 200 controls debug build takes around 7 sec)
    --> On creating 100 and 200 user controls the performance measures of WPF were identical to performance measures of release build in QT.
    --> but on increasing the loop size, i noticed QT performance was pretty bad w.r.t to WPF.
    for 1000 UserControls- WPF took - 7sec( creation + render time) and 137 MB of memory
    while QT took - 15 sec(creation+render time) and 147MB of memory

    for 10,000 usercontrols- WPF took - 79sec and 1 GB memory
    QT took - 22 mins for creation and rendering and 1GB of memory
    Note: Each UserControls Contains around 9 controls
    Can some one comment on
    -> Is QT Performance bad compared to WPF for huge number of controls?
    -> Is it the issue with the Rendering engine used by default. I'm using QT 5.4 64 bit Open source version of QT.
    -> the below states QT native rendering suffers with Performance issues - and Raster graphics to be used https://kjellkod.wordpress.com/2011/05/22/moving-to-qt5-will-that-remove-qts-performance-issues-on-linux/
    How to switch to Raster Graphics inQT 5? Understand that QApplication.SetGraphicsSystem has been deprecated in QT5.
    --> Is QT Quick better vs Widget application in terms of performance?

    Thanks in Advance,

  • Lifetime Qt Champion

    Hi and welcome to devnet,

    You should rather bring this topic on the interest mailing list you'll find there Qt's developers/maintainers (this forum use more user oriented)

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