Avoid sddm-greeter to have high CPU usage

Summary

My iMac having Ubuntu kept having high CPU usage with the program sddm-greeter.

Solution

Amending the file /etc/security/pam_env.conf fixed up the issue :

/etc/security/pam_env.conf
======
#
# Avoid high cpu usage with sddm-greeter
# https://github.com/sddm/sddm/issues/323
QT_QUICK_BACKEND DEFAULT=software

Reference

• high cpu when sddm-greeter is idle

Related Post

• Enable your Linux Machine to show login (SDDM) with Aerial Theme when motion is detected

Comments

[rulatir]

This is a very poor, nonspecific, whole-system reduction-in-functionality solution. It boils down to completely giving up on hardware accelaration in many important contexts. My KDE desktop looks different after enabling this workaround (e.g. desktop icon labels get background rectangles instead of being text-shaded) because a lot of code paths in KDE Plasma choose different, less CPU-intensive visual effects when software rendering is forced.