Arch Linux

AngryBeing

Member

Registered: 2020-05-05

Posts: 12

Discrete GPU laptop external graphical output lags if I close the lid

Hello,

I have a laptop with an Intel iGPU and an Nvidia GPU. I am using Arch with KDE. I am trying to use it on an external display with the laptop's display turned off (using only the HDMI connected monitor).

My computer only has a single HDMI port, and that comes from the discrete GPU (the Nvidia one). I have found some people pointing out online that this is an issue since the discrete GPU isn't considered the primary one by xorg, and that makes the graphical output lag if I either close the lid or disable the laptop's built-in display.

So the only way I can use the external monitor is if I also let the laptop's screen enabled. Otherwise, if I either close the lid or disable the laptop screen, my desktop has heavy stutters if I try to perform any mildly graphically intensive action such as dragging windows or selection boxes (the mouse cursor/pointer works fine though).

Is there any workaround for this where I can have a lag-free experience using only the external display, connected to the discrete GPU's HMDI port (the only one that I have)?

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 25,076

Re: Discrete GPU laptop external graphical output lags if I close the lid

Make sure PRIME sync is enabled by enabling KMS in the nvidia driver by setting the nvidia-drm.modeset=1 kernel parameter.

If that doesn't fix it you'll have to logically decouple them more, I'm assuming the config and setup described in https://wiki.archlinux.org/title/NVIDIA … phics_only should relevantly help.