[Development] QT5.x resource usage

Koehne Kai Kai.Koehne at digia.com
Mon Aug 5 13:19:21 CEST 2013

> -----Original Message-----
> From: development-bounces+kai.koehne=digia.com at qt-project.org
> [mailto:development-bounces+kai.koehne=digia.com at qt-project.org] On
> Behalf Of JaiJun Li
> Sent: Tuesday, July 16, 2013 1:01 PM
> To: development at qt-project.org
> Subject: [Development] QT5.x resource usage
> After transforming a gui project created and finished in QT4.8 to QT5.1, I
> found the CPU load is up to 100% in Task Manger, and RAM consumption is
> also much heavier.
> Please notice the parameters under no operation conditions:
> 4.8             CPU load is 0%, RAM consumption is 20M
> 5.1             CPU load is always in 25+% (4 cores), RAM consumption is 100+M
> Obviously, it continually refreshes UI in QT5.1.
> By analyzing UI and adding file one by one, I did find some of UI with circle
> animations cause high CPU load. But after I blocked these animations, the
> CPU load went up as the number of UI increased, and RAM consumption
> grew at the rate of dozens of hundreds of KB per second as well.
> Using QML Analyzer, it showed the refresh of animation timer in Painting
> occupy the system resource. And under no operation the refresh ratio also
> goes up to approximate 100 fps. At this time, no visual circle animation exists
> on UI. Even though I deleted circle animation it did not help. I guess the
> cause would be other one-time animations, because these animations may
> were not terminated correctly and were constantly sending refresh signals.

I guess you're still using Qt Quick 1 with Qt 5.1 ? Or did you try to port to QtQuick 2 at the same time?

If there are bindings triggering the painter updates they should show up in the QML Analyzer, too ...



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