The Linux session becomes slow when the monitor goes in sleep mode
We noticed this behaviour with a Linux machine equipped with NVIDIA GPU and any of the drivers of the 440 series, but we cannot exclude that it can happen also with other graphics cards.
When the monitor enters the sleep mode or it is disconnected, the GPU produces 1 frame per second (FPS) which is perceived by the user as a slowness of the NoMachine session.
As a workaround, you can disable the HardDPMS option in the NVIDIA X config file (e.g. xorg.conf.nvidia file):
Option "HardDPMS" "false"
You may find some more information about the problem in the NVIDIA Forum, e.g. https://forums.developer.nvidia.com/t/440-36-with-bumblebee-drops-to-1-fps-after-running-for-10-minutes/108431/5
Alternative workaround for XFCE desktop:
- Disable Composite via Start->Window Manager Tweaks->Compositor-> Disable
or from command line, run:
xfconf-query -c xfwm4 -p /general/use_compositing -s false
- Disable vsync, from command line:
xfconf-query -c xfwm4 -p /general/vblank_mode -s off
Alternative workaround for MATE desktop is to use Marco, a minimal X window manager:
MATE Tweak -> Windows -> Window Manager -> Marco (no compositor)