External Monitor works on prime-select nvidia but not on intel

Graphics / Linux Linux
1

I’m running a Lenovo ideapad laptop with AMD Ryzen 5 4600H processor + Nvidia GTX 1650Ti. I dual booted the system with Ubuntu 21.10 which uses the linux kernel 5.8.0-40-generic. I installed nvidia-drivers-460 from the additional drivers settings in Ubuntu. I also have a secondary monitor connected to the HDMI port.

My laptop works fine when set in prime-select nvidia, The monitor displays the screen, I am able to open nvidia-settings and modify the settings and also see nvidia-smi . But it consumes too much power. Therefore, I tried to switch to the integrated AMD renoir graphics card .

Once I run prime-select intel and restart the system, the second monitor is not being detected. I tried deleting /etc/X11/xorg.conf but it didn’t help. I also tried switching from gdm3 to lightdm but that also didn’t work.

Any way I could get he monitor working?

My xrandr output:

Screen 0: minimum 320 x 200, current 1920 x 1080, maximum 16384 x 16384
eDP connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 344mm x 193mm
   1920x1080     60.01*+
   1680x1050     60.01  
   1280x1024     60.01  
   1440x900      60.01  
   1280x800      60.01  
   1280x720      60.01  
   1024x768      60.01  
   800x600       60.01  
   640x480       60.01
1 Like
2

The external hdmi port is connected to the nvidia gpu, so if you turn it off, the external hdmi port is also off.

1 Like
3

Hey @generix , thanks for the info. I was also suspecting the same thing. Is there any way I could verify it, other than the fact that the monitor is not working. Also, can I somehow get it working on the prime-select on-demand mode?

4

The xrandr only shows the internal display, so the AMD gpu doesn’t have any other outputs.
The on-demand mode is currently a work-in-progress with amd/nvidia combos, so this can’t really be used now.
Edit: better said, on demand+external output is a WIP, on demand by itself works.

1 Like
5

So, the only way for me to reduce the usage is the quality settings in nvidia-settings panel. I guess I can manage with that. Thank you @generix !!