<![CDATA[Memory usage increases with window size?]]>I've noticed that memory usage on Qt applications increases proportionally to the size of the window. For example, maximizing a window on a 4k screen increases memory usage by ~30Mb. I found a stackoverflow question on this same topic but it is dated for 2013 and I believe is outdated (https://stackoverflow.com/questions/14211976/qt5-memory-usage-depends-on-window-size).

The answers simply explains it away as a 'Qt thing' due to how Qt draws things, which is fair, however I noticed that other applications don't do this, even though they are graphically 'heavier'. I'm guessing they employ some newer tech that I'm unaware of (I'm using Qt 5.6 for clarification.)

What is the difference between Qt applications and other applications (notepad++, photoshop, game launchers, vs code, basically I haven't found another application that behaves like a Qt app) that causes this memory-expensive behavior? Bonus points if I could make it go away haha.

]]>https://forum.qt.io/topic/132045/memory-usage-increases-with-window-sizeRSS for NodeTue, 08 Sep 2026 04:03:51 GMTTue, 16 Nov 2021 18:13:47 GMT60<![CDATA[Reply to Memory usage increases with window size? on Tue, 16 Nov 2021 22:27:12 GMT]]>@SGaist said in Memory usage increases with window size?:

Hi,

The answer is likely the raster engine of the widgets module and the age of your Qt version.

You should consider updating to something more recent that has high DPI support to compare.

I can't, I need to compile with MSVC2010 and 5.6 is the latest version that supports it from what I've read.

]]>https://forum.qt.io/post/690366https://forum.qt.io/post/690366Tue, 16 Nov 2021 22:27:12 GMT<![CDATA[Reply to Memory usage increases with window size? on Tue, 16 Nov 2021 20:17:25 GMT]]>Just tested it. I started my app with different window sizes on the same machine and did see memory use up with bigger display. Are you bothered by 30MB more memory use? It is not much.

]]>https://forum.qt.io/post/690344https://forum.qt.io/post/690344Tue, 16 Nov 2021 20:17:25 GMT<![CDATA[Reply to Memory usage increases with window size? on Tue, 16 Nov 2021 19:22:25 GMT]]>Hi,

The answer is likely the raster engine of the widgets module and the age of your Qt version.

You should consider updating to something more recent that has high DPI support to compare.

]]>https://forum.qt.io/post/690329https://forum.qt.io/post/690329Tue, 16 Nov 2021 19:22:25 GMT