Create the file: /etc/profile.d/kwin_triple_buffer.sh containing this line: export KWIN_TRIPLE_BUFFER=1 Make it executable: chmod +x /etc/profile.d/kwin_triple_buffer.sh
Then, either reboot or issue the following command (as user): source /etc/profile.d/kwin_triple_buffer.sh && kwin_x11 --replace ...