Qtwebengine ridulous cpu usage on tasks that firefox has no footprint on

I have an HTML Wallpaper plugin I am using and even when modifying the code I still cannot get the 21% GPU usage and 2 maxed CPU cores (1 for each wallpaper instance)

In firefox I can have 15 of this page open and still use less CPU && GPU than qtwebengine

Hi - it sounds like this might require a bug report to either the developer of the plugin you’re using, or possibly even upstream to Qt? From some quick searching around, QtWebEngine does seem to have a bit of a history of CPU usage issues:

https://bugs.kde.org/show_bug.cgi?id=474824