Scene Graph performance issue

[Krenar Qehaja]

Hi everyone,

First of all I hope I'm posting to the correct mailing list, as this is a
performance issue regarding Scene Graph.

I'm a vivid fan of Qt5 and I build it in daily basis.

The performance of Scene Graph on my machine is horrible. I don't
know the frame rate (as I don't know how measure it) but you can
tell that it's far from being good. On the other hand, QML1 apps
perform much better, maybe 45-50 fps (still not perfect but much
better).

I also tried to change the engine to Graphics View by using
--original-qml and --original-qml-raster flags, but still didn't notice
any change.

I'm using Nvidia's proprietary drivers (v.270.41.06) and Compiz runs
very smooth, and so do QtQuick3D apps.

So my question is: is the performance related to my gfx drivers (and
is there any chance to fix it) or is it because of the quality of code
that is probably being worked on (seems unlikely to me, because
of the video presentations I've seen, apps seemed to run quite good)?

P.S. Is there a way to measure the frame rate of QML (1 and 2) and
QtQuick3D apps?

Regards,
Krenar

[g***@nokia.com]

Hi Krenar,

We have noticed a few X11 issues with scenegraph, but overall performance is always superior to QML 1.

A few things to test:

1. use qmlscene, not qmlviewer
2. disable compiz. We have experienced it not playing nice with scene graph
3. Make sure you enable beam sync in the nvidia control panel. (nvidia-settings I think the tool is called)

If none of these help, then I would like to see the code you are running.

cheers,
Gunnar

Post by Krenar Qehaja
Hi everyone,
First of all I hope I'm posting to the correct mailing list, as this is a
performance issue regarding Scene Graph.
I'm a vivid fan of Qt5 and I build it in daily basis.
The performance of Scene Graph on my machine is horrible. I don't
know the frame rate (as I don't know how measure it) but you can
tell that it's far from being good. On the other hand, QML1 apps
perform much better, maybe 45-50 fps (still not perfect but much
better).
I also tried to change the engine to Graphics View by using
--original-qml and --original-qml-raster flags, but still didn't notice
any change.
I'm using Nvidia's proprietary drivers (v.270.41.06) and Compiz runs
very smooth, and so do QtQuick3D apps.
So my question is: is the performance related to my gfx drivers (and
is there any chance to fix it) or is it because of the quality of code
that is probably being worked on (seems unlikely to me, because
of the video presentations I've seen, apps seemed to run quite good)?
P.S. Is there a way to measure the frame rate of QML (1 and 2) and
QtQuick3D apps?
Regards,
Krenar
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http://lists.qt.nokia.com/mailman/listinfo/qt5-feedback

[Krenar Qehaja]

Hi Gunnar,

Thanks a lot for the reply.

Post by g***@nokia.com
3. Make sure you enable beam sync in the nvidia control panel. (nvidia-settings
I think the tool is called)

Beam sync (Sync to VBlank on my machine) did the trick, as apparently it was
turned off. Now the performance is flawless.

Cheers,
Krenar