Low refresh rate on the 4K monitor connected via Type-C (Kubuntu 22.10, wayland, RTX 3060 Mobile)

Laptop: Asus Zephyrus G503, Ryzen 5800, RTX 3060
OS: Kubuntu 22.10 / wayland
Driver: latest from 525 branch, installed from ubuntu repos


  1. Low refresh rate(30Hz) when i using external 4k 60Hz monitor connected via Type-C interface. Same problem on the Ubuntu 22.10 (Gnome / wayland). The refresh rate on the built-in display is normal (165Hz). Measured this through the utility glxgears.

  2. When this monitor connected via HDMI the refresh rate is ok, but the colors are a little ugly (Limited RGB space, i think). I couldn’t find instructions on how to switch the mode to Full RGB. There is a possibility?

nvidia-bug-report.log.gz (468.3 KB)

Since you’re using wayland, the logs are useless, I can’t even see which output is connected to what.
Which input on the monitor are you using over usb-c (usb-c, displayport, hdmi)?

Type-C - Type-C in the first case.
HDMI - HDMI in the second.
Cables from the monitor box and works fine on the Win11.

Report from X11 if it help. Configuration has not changed(Type-C - Type-C connection to monitor) :

nvidia-bug-report.log.gz (583.2 KB)

By the way, from X11 the refresh rate is normal ~60Hz in this configuration case.

Ok, the USB-C is definitely connected to the nvidia gpu and using a correct DisplayPort connection. Both Xorg and Wayland report having set the monitor to 60Hz but on Wayland, it’s actually running at half the refresh rate.
There was a bug report for Gnome Wayland
though this should be fixed long ago, maybe the nvidia driver broke again.

The HDMI port of your notebook is connected to the AMD igpu, so you would have to check with that regarding color space and color range (full/limited)

though this should be fixed long ago, maybe the nvidia driver broke again.

If the problem is in the driver, will it be fixed? :)

It’s a bit confusing, re-reading the bug report it seems the bug itself was never fixed though nvidia devs claimed so with v470. It was just not relevant anymore with v495 implementing GBM.
So it’s a bit odd that you’re now running into this. Maybe switch to Gnome, check for the line Created gbm renderer for '/dev/dri/card0' and if it appears, reopen the bug report.

I have the same issue with my 4K 60Hz monitor connected via USB-C/DP. In my case it is because the GPU memory clock always stays at the lowest, as can be seen with nvidia-smi -q –d CLOCK. It seems this is simply not enough for processing the bandwidth of the 4K 60Hz video stream because manually raising the memory clock to above 6000 with nvidia-smi -lmc 6000,7000 makes 60Hz refresh rate work again. But I think this is a driver issue as it should raise the memory clock automatically when 4K 60Hz output is in use, just like what it does with X11 session.

nvidia-smi -lmc 6000,7000

Amazing! Its worked! Thank u.
Definitely it’s a driver issue and should be fixed. What do you think about this, @generix ?

Other clocks are lowly too.

        Graphics                          : 210 MHz
        SM                                : 210 MHz
        Memory                            : 6000 MHz (**fixed**)
        Video                             : 907 MHz

Odd, this specific driver bug previously only occurred when using Xorg so it’s unusual that in your case this was only when using wayland.

Could you point me to the report of the bug you mentioned that affected Xorg?

Because I also noticed that, although a bit off-topic here, the memory clock frequency scaling is also not perfect for Xorg in this setup (reverse PRIME). Both the graphics core clock and the memory clock will constantly cycle between the minimum and the maximum levels even on idle, as reported in both nvidia-smi and the PowerMizer panel of nvidia-settings, although it can still maintain 4K 60Hz. Using the same nvidia-smi -lmc workaround actually makes it more stable, and reduces the overall power consumption by quite a few watts.

Switched to X11. Clocks are updated dynamically (normal behavior i guess)

        Graphics                          : 262 MHz
        SM                                : 262 MHz
        Memory                            : 405 MHz
        Video                             : 555 MHz

Will this bug be fixed? :)

IDK, I’m just another user. It’s also very hardware specific, only happening on some notebook models according to my observation. e.g. it’s not happening on my own one, the clocks adapting fine to the needed bandwidth.

Sorry, I thought you were an Nvidia developer. Do you know if there is a way to report this bug to the developers?

or send an email with your nvidia-bug-report.log to linux-bugs[at]nvidia.com

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