Screen tearing on an external monitor with NVIDIA RTX 3070

I’ve got a Lenovo Legion 5 Pro and I use an external monitor. I’m experiencing horizontal screen tearing when I scroll down/up and when I watch movies or youtube videos. This does not happen when I use the laptop’s screen. The external monitor is connected to the HDMI port.

System info: AMD Ryzen 7 5800H with Radeon Graphics NVIDIA RTX 3070 with Nvidia 470 Kernel 5.11.0-34-generic #36~20.04.1-Ubuntu SMP Fri Aug 27 08:06:32 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux 

I’ve got my system set to Nvidia Performance mode. If I set Power saving mode the monitor is not detected. If I set Nvidia On Demand, graphical performance on the external monitor slows to a crawl.

I’m looking for a solution for eliminating the screen tearing on the external monitor. It doesn’t matter if that solution switches off the Nvidia graphics card or not.

Thanks

2 Answers

I have the same laptop and I experienced a similar problem after I upgraded the kernel. To solve it, I downgraded the kernel to 5.11.0-31-generic (if you don't have it, install it with apt install linux-headers-5.11.0-31-generic (I'm not sure if you need to install some other things as well, like linux-image-5.11.0-31-generic, or if it will happen automatically).

Other things to make sure:

1. For met the external monitor works best with the nvidia propietary drivers and in the "Nvidia on-demand" setting
2. Make sure you select the Dynamic graphics mode in the bios (press F2 on start-up. I had to update the bios before that option showed up)
3. I used this redit post for my setup. I didn't have to add the PPA for a new kernel, because I'm on 21.04, but here are some quotes that helped me:
   • In the BIOS (F2 at lenovo screen) must set to HYBRID mode (now renamed to dynamic graphics mode, I think)
   • edit grub and add the entry amdgpu.backlight=0 to fix backlight control of the original monitor
   • Tip: Gnome users can use this extension to change nvidia or integrated mode easy:

I found a solution. Enabling "Force Full Composition Pipeline" eliminates screen tearing on the second screen.