[solved] Qt Quick 2 performance issues

Schneidi

Hello, I started a new project in which I need to render Qml content on an WQHD display (2560 x 1440).
And I'm still trying to get a pretty basic qml test to run fluently. But on the full resolution the rendering performance drops way below 10 fps.
The target system runs a AMD G-T56N dual core processor 1,6 GHz 3,5 GiB ram and a dedicated AMD Radeon HD 6310 graphics card.

My qml Test is nothing more than this:
@import QtQuick 2.0

Item {
id: grid_view
width: 800
height: 600

Rectangle {
    id: grid_view_bg
    anchors.fill: parent

    ListModel {
        id: employee_model
        ListElement { name: "User 1"; }
        ListElement { name: "User 2"; }
        ListElement { name: "User 3"; }
        ListElement { name: "User 4"; }
        ListElement { name: "User 5"; }
        ListElement { name: "User 6"; }
        ListElement { name: "User 7"; }
        ListElement { name: "User 8"; }
        ListElement { name: "User 9"; }
        ListElement { name: "User 10"; }
    }
    Component {
        id: employeeDelegate
        Item {
            id:employeeContainer
            width: 180;
            height: 200
            Rectangle {
                id:employeeBody
                anchors.fill: parent
                anchors.rightMargin: 5
                color: "red"
                border.color: "black"

                Rectangle {
                    id: employeeHeader
                    z:101
                    color: "#bbdbf3"
                    anchors.horizontalCenter: parent.horizontalCenter
                    width: parent.width
                    height: 40
                    Text {
                        anchors.centerIn: parent
                        text: '<b>Name:</b> ' + name
                    }
                    border.color: "black"

                }
            }
        }
    }
    ListView {
        anchors.fill: parent
        model: employee_model
        orientation: Qt.Horizontal
        delegate: employeeDelegate
    }
}

}@

The main.cpp:
@QGuiApplication app(argc, argv);

QtQuick2ApplicationViewer viewer;
viewer.setMainQmlFile&#40;QStringLiteral("qml/untitled/main.qml"&#41;&#41;;
viewer.show();

@

So I just used the predefined QtQuick 2 Application example to start with.
Even on my development system running an intel quad core with dedicated ATI Radeon HD 3450 the performance start to decrease at a 1920 x 1080 resolution. The higher the resolution gets the worse is the performance. At the full WQHD resolution it is just unusable.

What might be the problem here ?
I would expect that qt is capable of a way better performance than what i get right now.
Both cards support at least OpenGL 3 or higher.
What can i do to get the qml animation on the list scrolling to run smooth.

I could need some help with this one.
Thank you for any help.

sierdzio

Are you using Qt 5.2? What OS are you on? Have you compiled Qt yourself (or maybe we are talking about an ANGLE build)?

I think in Qt 5.2 you can bump the version number to QtQuick 2.1, BTW.

Schneidi

Hi,

I'm using Qt 5.1.1 compiled by myself on Ubuntu on both systems.
May there be any performance difference between 5.1.1 and 5.2 ?

sierdzio

Yes, the rendering engine has been significantly optimised (see "this":http://blog.qt.digia.com/blog/2013/09/02/new-scene-graph-renderer/ blog entry).

If possible, compile Qt with "-opengl desktop" flag. It will make the most of your GPU.

Schneidi

Ok thanks I'm going to compile Qt 5.2 with the opengl desktop flag and see what happens.

Schneidi

Hey thanks for the hint sierdzio.
It's amazing. On Qt5.2 the example runs so much better then with 5.1.1.
Awesome piece the new scene graph.

Thumbs up.

sierdzio

hey, great! I'm happy that it helped you :)