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Qt 5.5.1 30% slower than Qt 5.5.0 ?
after switching from Qt 5.5.0 to Qt 5.5.1 (both MSVC2013 64bit) the graphic animations of the same Qt Windows 7 64bit desktop application are running 30% slower.
The animation is drawing in a QWidget via QPainter and QFont.
Anyone know what the problem might be?
Hi and welcome to devnet,
Since it looks like it might be a severe regression. I'd recommend posting this question to the interest mailing list. You'll find there Qt's developers/maintainers (this forum is more user oriented)
thanks for the welcome and your recommendation to post this topic to the Qt interest mailing list. I'll do that.
Is there anybody else who noticed a slow down of his application after updating from Qt 5.5.0 to Qt 5.5.1?
Meanwhile after further testing I'm not sure if its only an graphic issue. Because a basic QWidget / QPainter test application did not show any slow down with Qt 5.5.1. So it might be a deeper issue.
All I can say is that my application runs 30% slower with QT 5.5.1 than with Qt 5.5.0.
So I downloaded both Qt versions again and made a clean install. And after recompiling the Qt 5.5.0 and Qt 5.5.1 versions of my application both ran slow !!
So I checked the files from the new downloaded Qt 5.5.0 an saw that there are new files in it: For instance Qt5Core.dll and Qt5Cored.dll are from 23 October 2015 !
So I went back to the initial QT 5.5.0 release with Qt5Core.dll and Qt5Cored.dll from date 11. August 2015. And the speed was there again !
There is definitely something wrong with the new Qt 5.5.1 release. But I'm not an Qt expert to find out which Qt module does the slow down.
In that case I'd recommend posting your findings and question on the interest mailing list You'll find there Qt's developers/maintainers (this forum is more user oriented)
ribtoks last edited by
@molter The same for me with no graphic animations, but ordinary qml controls. Did you figure out anything new? Patch or smth?