EDID shenanigans on Asus 2k monitor

General system Gaming, sound and video
1

Hello.

I have an Asus ROG PG278Q (1440p 144Hz, problematic gsync) that’s been working okay for years but is no longer correctly detected under Linux.

At the time of purchase I wasn’t aware of the issue as it didn’t present itself when using a hdmi->dp cable which is how I used it before building a new desktop.
(if it was set to 144Hz under Linux it was working fine.)

either way: It used to be detected correctly under Linux however this is no longer the case and I’m not sure why this is. Took me a while to troubleshoot but seemed like the power brick had given up so i ordered a replacement.

Now on the new brick it seemed to behave as usual for a few days and then it started to behave strange again.

Under Linux it’s currently detected as “unknown 640x480 60Hz” which the monitor doesn’t seem to support as it will not display a picture and the backlight has a stroboscope effect going on constantly.

In BIOS, before linux drivers load or under Win11 it is detected correctly and seems to work.

This really confuses me because if i try hooking up my laptop with win10 the monitor isn’t even detected at all.

Is this monitor dying or what’s going on?
I’m not sure myself…

2

have you try witth USB live iso ?
can you report

inxi -Fza 
xrandr
3

Livecd behaves the same, be it EOS or recent Ubuntu release, I’ll post inxi and xrandr output later.

4

This reeks of a hardware issue.

Try to restart with a MS Windows installation and see if it works there, but I doubt it.

Could be the monitor, but also could be the cable. Since the cable is less expensive, I would try to swap this out first.

5

Sorry if this was kind of buried and not elaborated on but “under Win11 it is detected correctly and seems to work”
And that was a clean install with the latest drivers.

On a new DP cable it behaves the same.

6 
$ inxi -Fza
System:
  Kernel: 6.14.4-arch1-2 arch: x86_64 bits: 64 compiler: gcc v: 15.1.1
    clocksource: tsc avail: hpet,acpi_pm
    parameters: initrd=\6c15a0c342ec4342b1e76c1d90f21738\6.14.4-arch1-2\initrd
    nvme_load=YES nowatchdog rw
    root=UUID=e3df332f-eec3-4caa-8ab2-76833c1f23a6
    systemd.machine_id=6c15a0c342ec4342b1e76c1d90f21738
  Desktop: KDE Plasma v: 6.3.4 tk: Qt v: N/A info: frameworks v: 6.13.0
    wm: kwin_wayland vt: 1 dm: SDDM Distro: EndeavourOS base: Arch Linux
Machine:
  Type: Desktop Mobo: ASRock model: X470 Taichi serial: <superuser required>
    uuid: <superuser required> UEFI: American Megatrends v: P10.31
    date: 08/22/2024
Battery:
  Device-1: hidpp_battery_0 model: Logitech M570 serial: <filter> charge: 65%
    rechargeable: yes status: discharging
CPU:
  Info: model: AMD Ryzen 7 3800X bits: 64 type: MT MCP arch: Zen 2 gen: 2
    level: v3 note: check built: 2020-22 process: TSMC n7 (7nm)
    family: 0x17 (23) model-id: 0x71 (113) stepping: 0 microcode: 0x8701034
  Topology: cpus: 1x dies: 1 clusters: 1 cores: 8 threads: 16 tpc: 2
    smt: enabled cache: L1: 512 KiB desc: d-8x32 KiB; i-8x32 KiB L2: 4 MiB
    desc: 8x512 KiB L3: 32 MiB desc: 2x16 MiB
  Speed (MHz): avg: 1758 min/max: 550/4560 boost: enabled scaling:
    driver: amd-pstate-epp governor: powersave cores: 1: 1758 2: 1758 3: 1758
    4: 1758 5: 1758 6: 1758 7: 1758 8: 1758 9: 1758 10: 1758 11: 1758 12: 1758
    13: 1758 14: 1758 15: 1758 16: 1758 bogomips: 124812
  Flags: avx avx2 ht lm nx pae sse sse2 sse3 sse4_1 sse4_2 sse4a ssse3 svm
  Vulnerabilities:
  Type: gather_data_sampling status: Not affected
  Type: ghostwrite status: Not affected
  Type: itlb_multihit status: Not affected
  Type: l1tf status: Not affected
  Type: mds status: Not affected
  Type: meltdown status: Not affected
  Type: mmio_stale_data status: Not affected
  Type: reg_file_data_sampling status: Not affected
  Type: retbleed mitigation: untrained return thunk; SMT enabled with STIBP
    protection
  Type: spec_rstack_overflow mitigation: Safe RET
  Type: spec_store_bypass mitigation: Speculative Store Bypass disabled via
    prctl
  Type: spectre_v1 mitigation: usercopy/swapgs barriers and __user pointer
    sanitization
  Type: spectre_v2 mitigation: Retpolines; IBPB: conditional; STIBP:
    always-on; RSB filling; PBRSB-eIBRS: Not affected; BHI: Not affected
  Type: srbds status: Not affected
  Type: tsx_async_abort status: Not affected
Graphics:
  Device-1: NVIDIA GP104 [GeForce GTX 1080] driver: nouveau v: kernel
    non-free: 550-570.xx+ status: current (as of 2025-04; EOL~2026-12-xx)
    arch: Pascal code: GP10x process: TSMC 16nm built: 2016-2021 pcie: gen: 1
    speed: 2.5 GT/s lanes: 1 link-max: gen: 3 speed: 8 GT/s lanes: 16 ports:
    active: none empty: DP-1, DP-2, DP-3, DVI-D-1, HDMI-A-1 bus-ID: 09:00.0
    chip-ID: 10de:1b80 class-ID: 0300
  Device-2: Advanced Micro Devices [AMD/ATI] Navi 48 [RX 9070/9070 XT]
    vendor: Sapphire driver: amdgpu v: kernel pcie: gen: 5 speed: 32 GT/s
    lanes: 16 ports: active: DP-5,HDMI-A-2 empty: DP-4,HDMI-A-3,Writeback-1
    bus-ID: 10:00.0 chip-ID: 1002:7550 class-ID: 0300
  Display: wayland server: X.org v: 1.21.1.16 with: Xwayland v: 24.1.6
    compositor: kwin_wayland driver: X: loaded: amdgpu,modesetting
    unloaded: radeon alternate: fbdev,nouveau,nv,vesa dri: radeonsi,nouveau
    gpu: amdgpu d-rect: 2560x1080 display-ID: 0
  Monitor-1: DP-5 pos: right res: mode: 640x480 hz: 60 scale: 100% (1)
    size: N/A modes: 640x480
  Monitor-2: HDMI-A-2 pos: primary,left model: Dell P2211H serial: <filter>
    built: 2011 res: mode: 1920x1080 hz: 60 scale: 100% (1) dpi: 102 gamma: 1.2
    size: 477x268mm (18.78x10.55") diag: 547mm (21.5") ratio: 16:9 modes:
    max: 1920x1080 min: 720x400
  API: EGL v: 1.5 hw: drv: nvidia nouveau drv: amd radeonsi platforms:
    device: 0 drv: radeonsi device: 1 drv: nouveau device: 2 drv: swrast gbm:
    drv: kms_swrast surfaceless: drv: radeonsi wayland: drv: radeonsi x11:
    drv: radeonsi
  API: OpenGL v: 4.6 compat-v: 4.3 vendor: amd mesa v: 25.0.5-arch1.1
    glx-v: 1.4 direct-render: yes renderer: AMD Radeon Graphics (radeonsi
    gfx1201 ACO DRM 3.61 6.14.4-arch1-2) device-ID: 1002:7550
    memory: 15.62 GiB unified: no display-ID: :1.0
  API: Vulkan Message: No Vulkan data available.
  Info: Tools: api: clinfo, eglinfo, glxinfo, vulkaninfo
    de: kscreen-console,kscreen-doctor wl: wayland-info
    x11: xdpyinfo, xprop, xrandr
Audio:
  Device-1: NVIDIA GP104 High Definition Audio driver: snd_hda_intel v: kernel
    pcie: gen: 1 speed: 2.5 GT/s lanes: 1 link-max: gen: 3 speed: 8 GT/s
    lanes: 16 bus-ID: 09:00.1 chip-ID: 10de:10f0 class-ID: 0403
  Device-2: Advanced Micro Devices [AMD/ATI] driver: snd_hda_intel v: kernel
    pcie: gen: 5 speed: 32 GT/s lanes: 16 bus-ID: 10:00.1 chip-ID: 1002:ab40
    class-ID: 0403
  Device-3: Advanced Micro Devices [AMD] Starship/Matisse HD Audio
    vendor: ASRock driver: snd_hda_intel v: kernel pcie: gen: 4 speed: 16 GT/s
    lanes: 16 bus-ID: 12:00.4 chip-ID: 1022:1487 class-ID: 0403
  API: ALSA v: k6.14.4-arch1-2 status: kernel-api
    tools: alsactl,alsamixer,amixer
  Server-1: PipeWire v: 1.4.2 status: active with: 1: pipewire-pulse
    status: active 2: wireplumber status: active 3: pipewire-alsa type: plugin
    4: pw-jack type: plugin tools: pactl,pw-cat,pw-cli,wpctl
Network:
  Device-1: Intel Dual Band Wireless-AC 3168NGW [Stone Peak] driver: iwlwifi
    v: kernel pcie: gen: 1 speed: 2.5 GT/s lanes: 1 bus-ID: 08:00.0
    chip-ID: 8086:24fb class-ID: 0280
  IF: wlan0 state: up mac: <filter>
  Device-2: Intel I211 Gigabit Network vendor: ASRock driver: igb v: kernel
    pcie: gen: 1 speed: 2.5 GT/s lanes: 1 port: c000 bus-ID: 0a:00.0
    chip-ID: 8086:1539 class-ID: 0200
  IF: enp10s0 state: down mac: <filter>
  Info: services: NetworkManager, systemd-timesyncd, wpa_supplicant
Bluetooth:
  Device-1: Intel Wireless-AC 3168 Bluetooth driver: btusb v: 0.8 type: USB
    rev: 2.0 speed: 12 Mb/s lanes: 1 mode: 1.1 bus-ID: 1-9:2 chip-ID: 8087:0aa7
    class-ID: e001
  Report: btmgmt ID: hci0 rfk-id: 0 state: down bt-service: disabled
    rfk-block: hardware: no software: no address: N/A
Drives:
  Local Storage: total: 2.25 TiB used: 8.44 GiB (0.4%)
  SMART Message: Unable to run smartctl. Root privileges required.
  ID-1: /dev/nvme0n1 maj-min: 259:0 vendor: Samsung model: PM961 NVMe 512GB
    size: 476.94 GiB block-size: physical: 512 B logical: 512 B speed: 31.6 Gb/s
    lanes: 4 tech: SSD serial: <filter> fw-rev: CXY74D1Q temp: 28.9 C
    scheme: GPT
  ID-2: /dev/nvme1n1 maj-min: 259:3 vendor: Mushkin model: MKNSSDHL1TB-D8
    size: 931.51 GiB block-size: physical: 512 B logical: 512 B speed: 31.6 Gb/s
    lanes: 4 tech: SSD serial: <filter> fw-rev: T0709E0L temp: 33.9 C
    scheme: GPT
  ID-3: /dev/sda maj-min: 8:0 vendor: SanDisk model: SSD PLUS 480GB
    size: 447.14 GiB block-size: physical: 512 B logical: 512 B speed: 6.0 Gb/s
    tech: SSD serial: <filter> fw-rev: 00RL scheme: GPT
  ID-4: /dev/sdb maj-min: 8:16 vendor: SanDisk model: SSD PLUS 480GB
    size: 447.14 GiB block-size: physical: 512 B logical: 512 B speed: 6.0 Gb/s
    tech: SSD serial: <filter> fw-rev: 00RL scheme: GPT
Partition:
  ID-1: / raw-size: 475.94 GiB size: 467.4 GiB (98.21%) used: 8.35 GiB (1.8%)
    fs: ext4 dev: /dev/nvme0n1p2 maj-min: 259:2
Swap:
  Alert: No swap data was found.
Sensors:
  System Temperatures: cpu: 34.0 C mobo: 28.5 C
  Fan Speeds (rpm): fan-1: 1020
  GPU: device: amdgpu temp: 29.0 C mem: 52.0 C fan: 6 watts: 10.00
    device: nouveau temp: 36.0 C fan: 0
Info:
  Memory: total: 64 GiB note: est. available: 62.71 GiB used: 2.23 GiB (3.5%)
  Processes: 359 Power: uptime: 5m states: freeze,mem,disk suspend: deep
    avail: s2idle wakeups: 0 hibernate: platform avail: shutdown, reboot,
    suspend, test_resume image: 25.07 GiB services: org_kde_powerdevil,
    power-profiles-daemon, upowerd Init: systemd v: 257 default: graphical
    tool: systemctl
  Packages: pm: pacman pkgs: 1011 libs: 234 tools: yay Compilers:
    gcc: 15.1.1 Shell: Bash v: 5.2.37 running-in: konsole inxi: 3.3.38

$ xrandr
Screen 0: minimum 16 x 16, current 2560 x 1080, maximum 32767 x 32767
HDMI-A-2 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 477mm x 268mm
   1920x1080     59.96*+
   1440x1080     59.99
   1400x1050     59.98
   1280x1024     59.89
   1280x960      59.94
   1152x864      59.96
   1024x768      59.92
   800x600       59.86
   640x480       59.38
   320x240       59.29
   1680x1050     59.95
   1440x900      59.89
   1280x800      59.81
   1152x720      59.97
   960x600       59.63
   928x580       59.88
   800x500       59.50
   768x480       59.90
   720x480       59.71
   640x400       59.95
   320x200       58.14
   1600x900      59.95
   1368x768      59.88
   1280x720      59.86
   1024x576      59.90
   864x486       59.92
   720x400       59.27
   640x350       59.28
DP-5 connected 640x480+1920+0 (normal left inverted right x axis y axis) 0mm x 0mm
   640x480       59.38*+
   320x240       59.29
   640x400       59.20
   320x200       58.14
   640x350       59.28

Edit: i have no idea why nvidia is assumed to be “gpu 1” regardless if i swap the cards around or not. The Nvidia card has no monitors connected and should really be the second gpu (according to system layout) but for some stupid reason it gets priority in the device list. (I intend to use it only for CUDA later)

The good and the questionable monitor are both hooked up to the AMD card only.

7

you omit that you have 2 videos cards
is it with Radeon 9070 / 9070 RT that you try with hdmi ?

recheck DP cable

Monitor-1: DP-5 pos: right res: mode: 640x480 hz: 60 scale: 100% (1)
    size: N/A modes: 640x480

about AMD and HDMI 2.1

8

Hmm?
I can remove either gpu and the issue remains. I should clarify: this monitor only has a single DP port so i tried replacing the DP cable i already had. It is a DP 1.4 cable though which is good enough for 1440p 240Hz from what i’ve read.

The monitor on HDMI is an old Dell 1080p just so that I can see anything when drivers are loaded under linux. (it is of little importance)

When I tested hooking up the Asus monitor to my laptop it was by using a hdmi->dp adapter cable (it is not detected at all this way)