Samsung G80SD cap at 120hz instead 240hz

General system Kernel, boot, graphics & hardware
1

Hello dear community, i have been trying to work around an issue that i have for a couple of days now.
As a former windows user for over 20 years im so happy i did the pull for a better and stable OS, endeavourOS ofc :slight_smile:

So going back to the problem im trying to work around, the g80sd on display settings cap at 120hz and the 240 hz option does not appear at all.

i’ve been looking around and found this thread in other forum. https://gitlab.freedesktop.org/drm/amd/-/issues/3718

They have seem to fixed this issue on their own way, but im a newbie on this OS sofar and i dont know how to exactly fix this problem. I have already tried actually, no success.

Any help is welcome, devs of EndeavourOS would be able to fix this fast with their knowledge most likely, fingers crossed.

Cheers, RayaNN017

2

Not much help I can provide. Looking on threads either you will go on a journey of trying to implement this workaround: https://bbs.archlinux.org/viewtopic.php?id=297515

or just wait till commit will land in kernel.

3

Welcome to the community @RayaNN017 :wave::partying_face: :enos_flag:

How have you got your monitor connected to your system? Is it via HDMI, or DisplayPort? Are you using any adaptors (eg: HDMI to DisplayPort conversion)?

This will offer us some basic system details:

inxi -SMGxxx --za

I would suggest that pure DisplayPort is the preferred option, as the HDMI 2.1 spec conflicts with open-source licensing.

4

thanks mate for your comment. It can be frustating when u try everything can u cant get there.

5

Hello Bink, thanks.

my system is connected via hmd atm.
i cannot use DP at all , cause it random flickers, white strips etc… BUT i can do another log if needed with DP

here is the log:

System:
Kernel: 6.13.8-arch1-1 arch: x86_64 bits: 64 compiler: gcc v: 14.2.1
clocksource: tsc
Desktop: KDE Plasma v: 6.3.4 tk: Qt v: N/A wm: kwin_wayland vt: 1 dm: SDDM
Distro: EndeavourOS base: Arch Linux
Machine:
Type: Desktop Mobo: ASRock model: X870E Taichi serial:
uuid: UEFI: American Megatrends LLC. v: 3.20
date: 02/21/2025
Graphics:
Device-1: Advanced Micro Devices [AMD/ATI] Navi 31 [Radeon RX 7900 XT/7900
XTX/7900 GRE/7900M] vendor: ASRock driver: amdgpu v: kernel arch: RDNA-3
pcie: speed: 16 GT/s lanes: 16 ports: active: HDMI-A-1 empty: DP-1, DP-2,
DP-3, Writeback-1 bus-ID: 03:00.0 chip-ID: 1002:744c class-ID: 0300
Device-2: Advanced Micro Devices [AMD/ATI] Granite Ridge [Radeon Graphics]
vendor: ASRock driver: amdgpu v: kernel pcie: speed: 16 GT/s lanes: 16
ports: active: none empty: DP-4, DP-5, DP-6, HDMI-A-2, Writeback-2
bus-ID: 7c:00.0 chip-ID: 1002:13c0 class-ID: 0300 temp: 36.0 C
Display: wayland server: X.org v: 1.21.1.16 with: Xwayland v: 24.1.6
compositor: kwin_wayland driver: X: loaded: amdgpu
unloaded: modesetting,radeon alternate: fbdev,vesa dri: radeonsi
gpu: amdgpu display-ID: 0
Monitor-1: HDMI-A-1 model: Samsung Odyssey G80SD serial: res:
mode: 3840x2160 hz: 120 scale: 145% (1.45) to: 2648x1490 dpi: 139
size: 700x400mm (27.56x15.75") diag: 801mm (31.5") modes: max: 3840x2160
min: 640x480
API: EGL v: 1.5 hw: drv: amd radeonsi platforms: device: 0 drv: radeonsi
device: 1 drv: radeonsi device: 2 drv: swrast gbm: drv: radeonsi
surfaceless: drv: radeonsi wayland: drv: radeonsi x11: drv: radeonsi
API: OpenGL v: 4.6 compat-v: 4.5 vendor: amd mesa v: 25.0.3-arch1.1
glx-v: 1.4 direct-render: yes renderer: AMD Radeon RX 7900 XTX (radeonsi
navi31 LLVM 19.1.7 DRM 3.61 6.13.8-arch1-1) device-ID: 1002:744c
display-ID: :1.0
API: Vulkan v: 1.4.309 layers: 5 surfaces: xcb,xlib,wayland device: 0
type: discrete-gpu driver: N/A device-ID: 1002:744c device: 1
type: integrated-gpu driver: N/A device-ID: 1002:13c0
Info: Tools: api: clinfo, eglinfo, glxinfo, vulkaninfo
de: kscreen-console,kscreen-doctor gpu: amdgpu_top,lact wl: wayland-info
x11: xdpyinfo, xprop, xrandr

6

AMD GPU’s use open source drivers on Linux.
The HDMI Forum does not release HDMI 2.1 code under an open-source friendly license. This is an impasse.

If using HDMI, 4K @ 240Hz is only possible using HDMI 2.1.
1080p @ 240Hz is fully supported by HDMI 2.0, and 1440p @ 240Hz has limited support.

See Refresh frequency limits for standard video.

I’d suggest troubleshooting the DisplayPort issues. Do you have another good quality DisplayPort cable you can test with?

7

Phoronix | HDMI Forum Rejects Open-Source HDMI 2.1 Driver Support Sought By AMD

One of the limitations of AMD’s open-source Linux graphics driver has been the inability to implement HDMI 2.1+ functionality on the basis of legal requirements by the HDMI Forum. AMD engineers had been working to come up with a solution in conjunction with the HDMI Forum for being able to provide HDMI 2.1+ capabilities with their open-source Linux kernel driver, but it looks like those efforts for now have concluded and failed.

Thus a sad day for open-source GPU drivers with no apparent solution to safely implement HDMI 2.1+ functionality within open-source display drivers…
Needless to say, open-source Linux advocates should try to use DisplayPort instead if at all possible.

8

Time and sometimes frustration - price we pay for Linux :wink:

1 Like
9

i see this only a bet in the dark but tried using vulkan drivers?


extra/amdvlk 2025.Q1.3-1 (20.6 MiB 82.4 MiB) 
    AMD's standalone Vulkan driver
extra/vulkan-radeon 1:25.0.3-1 (2.7 MiB 12.8 MiB) 
    Open-source Vulkan driver for AMD GPUs

Personal, I omit HDMI and prefer DP here too. But Cable quality matters a lot, and cable specifications too.

What i do not see here is aslo if you tried to set this on a X11 session instead of wayland? and giving the output of this under a X11 session:

xrandr | eos-sendlog or run xrandr and pst it here if its not 4 miles long :wink:

10

I am aware that hdmi 2.1 is not supported in my OS, the only reason i was using it, is the screentearing and flickering effects not being seen.
Today, in the morning, ive swapped back to DP1.4, the cable is high quality.
My screen, Samsung g80sd, does not support 2.1 DP and the cable i actually use is high quality one from goobay. I do not have any of this Problems with 240hz on windows, only on wayland plasma.
According to the link i sent above this seem to be a problem from kernel parameters not getting the correct information from screen.
On xrandr command i cannot find the 240hz refresh rate at all. Ive also tried X11 aswell. No luck, and the colors seem bad as hell. Wayland plasma is important for me because hdr support. Colors blew up my mind right away. The only way i see to fix this refresh rate issue is by fixing the kernel parameters. Again, im not experienced enough to make it by myself, ive already tried alot of times to force edid into dracut and grub loader but no success.

11

Hello Joe, sadly on x11 the colors look worse and no hdr support which is important for me and my gaming machine. Ive installed the vulkan and amdvlk packages from sudo pacman command and nothing have changed after a couple reboots..
Does it hurt to keep both packages installed? Would it improve drivers stability?
My DP1.4 cable is High quality and i dont see advantages in purchasing 2.1 one since my display does not support above 1.4, correct me if i am wrong.
I can live with 4k 120hz since i have better hdr then in windows, more stability with 7900xtx running at 3300mhz, and colors are incredible.

12

I higher spec cable isn’t usually a disadvantage (aside from purchase cost), but I suspect you’re correct, it will not solve the issue.

Unfortunately upon investigation, to achieve 4K HDR with DisplayPort 1.4, the highest refresh rate officially supported is a mere 60Hz. You might potentially be able to tweak that up a bit higher, perhaps to 98Hz, but I wouldn’t count on any higher than that based on this table:

Note that DisplayPort 1.4 supports up to HBR3 / 32.4 Gbit/s, so use that as your upper limit.

For non-HDR content, 4K @ 120Hz is fully supported. But at 144Hz and 240Hz, compression and/or chroma subsampling is used and you will see a quality hit, as you’ve described.

So these are your options:

4K HDR10:

4K non-HDR10:

DisplayPort still looks like your best bet in either case, you just can’t push it so high.

It’s unfortunate your monitor doesn’t support DisplayPort 2.1, your GPU looks like it does. DisplayPort 2.1 can deliver 4K HDR @ 240Hz.

These are things Linux + AMD GPU users unfortunately have to factor in.

13

17441975535516440851428855276228
174419755355164408514288552762281800Ă—4080 664 KB

Finally got it working. If anyone need help , please poke me. Im happy to help!

14

So what did you do to fix it ?

1 Like
15

A trade-off perhaps?

16

yes i am hugely interested too on what you’re done to get it working!

17

Stay tuned, tonight i will do a guide “noob friendly” so its easy for everyone.

1 Like
18

After some days of research and trying to put this to work i did finally made this work for me.
This guide requires the same steps i have done to fully work!

Guide for 240Hz Monitor Override with custom EDID

Fresh installation of EndeavourOS was done, distro KDE PLASMA.
Bootloader : Grub-bootloader, I DO NOT KNOW if with defaultbootloader works!

This guide is specifically for the G80SD model (3840x2160 - 240Hz - VA - FreeSync Premium PRO - FreeSync range 60-240Hz - HDR/HDR10+).

Step 1:
Copy your custom edid to the firmware directory using “open as admin right click” and paste.

sudo cp g80.bin /usr/lib/firmware/edid/g80.bin

Edit the initramfs configuration file:

sudo nano /etc/mkinitcpio.conf

Add the EDID path to the FILES array:

FILES=(/usr/lib/firmware/edid/g80.bin)

Regenerate the initramfs:

sudo mkinitcpio -P

This step, editing can be done traditional way by editing via notepad. For those that doesn’t want to use console. Regenerating must be done on console.
Quick logout and re-log for step 2.

Step 2:
Edit the GRUB configuration file:

sudo nano /etc/default/grub

Add the following parameter to GRUB_CMDLINE_LINUX_DEFAULT:

drm.edid_firmware=DP-1:edid/g80.bin

!!(EnsureDP-1 is your actual Display-Port connector, otherwise change it; this METHOD requires a Display-Port connection)!!!
DO NOT DELETE THE PER-EXISTING CODE IN THERE. (also my failure on previous attempts)

Regenerate the bootloader configuration:

sudo grub-mkconfig -o /boot/grub/grub.cfg

Make sure BEFORE you proceed your monitor is up-to-date.

This method uses the full potential from your screen.

Additional notes:

The G80SD is a matte coated display that has vaporchamber cooling solution and allow you to hack on the service menu increasing the potential of HDR. !!This might void your warranty!!

This monitor also has several ways of using HDR, either with HDR on basic (more native colors) or with HDR OFF (more accurate colors) . The HDR OFF does not turns off HDR but works without HGIG in a different way. i have tested both methods and i prefear a more accurate state of image.

What i have won with the change to EndeavourOS:

More colorful, games look so crisp.
HDR full support, that is why i bought this monitor too.
Stability with 7900XTX EVC MOD to reach 3400MHZ Clocks / 2800 Mem (samsung mem required)

I HOPE, really, that this will help more people to make the jump after being so long windows users as i was. Never going back, ever.

Any questions i am happy to answer, further contact besides this forum E-mail

19

To clarify, you have 4K HDR10 @ 240Hz running via DisplayPort 1.4?

1 Like
20

It must be made possible with Display Stream Compression (DSC).

4k HDR @ 240Hz requires 68.56Gbit/s.
DisplayPort 1.4 max data rate is 25.92Gbit/s.

That’d be a DSC compression ratio of at least 2.65:1, which is within DSC’s range of capability if I’m not mistaken.

1 Like