4k 144hz not working on newer Nvidia drivers

My newly aquired Gigabyte M32U won’t go beyond 98hz in 4k in Windows 120 and 144 are available.
It’s display port with a proper cable. No HDMI 2.1 support problems.
I’ve tried increasing HorizSync in xorg.conf but nothing.
Tried adding Modelines but got BadMatch errors.
After some scary back and forth with the GPU drivers I’m currently on nvidia driver version 470xx and 144hz is available.
I had to rename xorg.conf and xorg.conf.d via terminal to not boot into blackscreen after that. There is currently no config for X11.
Performance on this old driver is pretty horiffic. Moving windows is kind of a slideshow. Haven’t dared to start games yet.

I actually want to upgrade to a 40series Nvidia card(currently gtx1080) for my new monitor but all the driver problems make me question my choice.

I’d like to get this monitor running at 4k 144hz with new drivers but GPU upgrade recommendations are also welcome if they solve this problem.

Hello @Rusticus :wink:

Since your monitor supports 4K 144Hz 4:4:4 with DSC or 4K 144Hz 4:2:0:

M32U Gaming Monitor Specification | Monitors - GIGABYTE U.S.A.

Try to use the color spaceYCbCr420 instead of YCbCr444: Appendix B. X Config Options

If using YCbCr444 on Windows and 120/144hz is available then Chroma Subsampling e.g. Compression (DSC) must be in use. If not, then YCbCr420. That is due the bandwidth limits.

If you rename the configs for the nvidia driver, what driver is then in use? Nvidia’s driver obviously not although installed.

Hello @megavolt
thanks so much for your answer. I havent thaught about that. Windows is running 4k144 with YCbCr422.
My GTX 1080 doesn’t support DSC as far as I’ve read but Linux seems to do by now. Maybe just getting a HDMI 2.1 DP2.0 and DSC compatible GPU will just fix the issue, right?

inxi -G  :heavy_check_mark:
Device-1: NVIDIA GP104 [GeForce GTX 1080] driver: nvidia v: 470.223.02
Device-2: Logitech Webcam Pro 9000 driver: snd-usb-audio,uvcvideo
type: USB
Display: x11 server: X.Org v: 21.1.10 with: Xwayland v: 23.2.3 driver: X:
loaded: modesetting,nouveau,nvidia unloaded: vesa gpu: nvidia resolution:
1: 3840x2160 2: N/A
API: EGL v: 1.5 drivers: kms_swrast,nvidia,swrast
platforms: gbm,x11,surfaceless,device
API: OpenGL v: 4.6.0 compat-v: 4.5 vendor: nvidia mesa v: 470.223.02
renderer: NVIDIA GeForce GTX 1080/PCIe/SSE2
API: Vulkan v: 1.3.274 drivers: nvidia surfaces: xcb,xlib

I seem to be on nvidia 470 driver. Any idea why the 470 driver uses the lower color space to allow 144hz and the newer doesnt?

I don’t think so. 470xx must default to 4:2:2, while newer drivers default to 4:4:4. So the highest possible color space. The reason why you get 98hz on 4k:8bit:444 is because of HBR3 (DP1.4) which has 8.10 Gbps bandwidth per lane. Due to bandwidth limits of the cable/connectors it needs sacrifice something to get 144hz: Color, resolution, chroma. On Linux and on Mac as well, the driver decides to prefer a better picture than a higher refresh rate, and it sacrifice the refresh rate in favor of a better picture. 470xx seems to sacrifice the color or is just not capable of YCbCr444, just like on Windows.

So you would need to replace the GPU, the Monitor and the cable to achieve your goal, if you don’t want to sacrifice the quality of the picture and get the highest possible refresh rate.

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Impressive knowledge there! Thanks for the help so far.

Monitor is rated for 4:4:4 with DSC. If I get a HDMI 2.1 Cable and a DSC compatible GPU I should be able to run 4k 144hz 4:4:4. Thinking about 7800xt at the moment.
Question is will Linux just work, or do I have to spend hours in the console recompling graphics drivers with certain flags to enable dsc?

Why do you think I’d have to switch out the monitor?

Well I believe your card is able to run it with DSC, but not with 470xx, since this driver has zero support for DSC. It has to be the current driver, at least 530xx (where it started to support).

Because it is limited to DP1.4. DP2.0 is the way to go without DSC. Take a look here: DisplayPort - Wikipedia You would need at least UHBR10 to get 4k:8bit:444@144hz without DSC.

HDMI is good for Videos, Movies or where high refresh rates doesn’t matter.

No, in general it should work out-of-the-box. Maybe some driver parameters are needed, but no recompiling. I am not an high expert of the amdgpu driver, but as I know DSC is supported although there are problems when you use a widescreen, which has 2 Monitors inside. When you use one DP2.0 cable to connect both with DSC.

Thanks a lot for your help. I’ve bought a 7800xt now and it seems to “just work”. 144hz is running. I don’t know if it’s 422 but it doesn’t look like it. Won’t check. If I’d find out it’s actually 422 it would bother me.

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:ok_hand: :+1:
mark your post as solved

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