Arch Linux

reloadedd

Member

Registered: 2023-07-06

Posts: 12

[SOLVED] Can't set 4k@120Hz on LG C3

Hello everyone,

I just received this TV (LG C3) that I plan to use as a monitor. I have a Lenovo Legion 5 laptop with Ryzen 4800H & Nvidia GTX 1650 Ti. I also have dual boot with Windows 11 and they are on separate SSDs, the Windows' partitions are on the factory SSD and the Linux ones are on a second SSD that I've installed. Speaking of Linux, I'm using Arch Linux running KDE Plasma 6 on Wayland.

The problem is that I don't have the 120 Hz as an option for the refresh rate on Display Configuration. And this is for 4K only, for 1440p and 1080p I do get the 120 Hz option. And to rule out the obvious, the HDMI cable is 2.1 and supports 8K@60Hz, 4K@120Hz, 48Gbps and I tend to believe it. Moreover, on Windows I do get the 120Hz refresh rate and Windows it's not faking it. At first I didn't get 120 Hz on Windows, only 60 Hz and that was because Game Optimiser was not enabled in the TV menu (and on Linux I could get only 30 Hz). After enabling it the 120 Hz option appeared on Windows. The TV options that I set are the following:
- Game Optimiser on both Picture & Sound
- Game Optimiser toggle set to ON
- VRR & G-sync and ALLM enabled on Game Optimiser menu, AMD Freesync Premium is disabled
- The HDMI input is set to PC mode

I don't have the latest nvidia driver because of the flickering issue on Wayland, which is more aggravated on the latest version, I downgraded it to 535.171.04, on which I still experience flickering, but it's more acceptable. Here is some info that I hope is useful. If more info is needed, I'm glad to help.

❯ neofetch
                   -`                    reloadedd@Hades 
                  .o+`                   --------------- 
                 `ooo/                   OS: Arch Linux x86_64 
                `+oooo:                  Host: 82B5 Lenovo Legion 5 15ARH05
               `+oooooo:                 Kernel: 6.8.4-arch1-1 
               -+oooooo+:                Uptime: 1 hour, 7 mins 
             `/:-:++oooo+:               Packages: 1947 (pacman), 19 (flatpak) 
            `/++++/+++++++:              Shell: fish 3.7.1 
           `/++++++++++++++:             Resolution: 3840x2160 
          `/+++ooooooooooooo/`           DE: Plasma 6.0.3 
         ./ooosssso++osssssso+`          WM: kwin 
        .oossssso-````/ossssss+`         WM Theme: Klassy 
       -osssssso.      :ssssssso.        Theme: MontereyDark [Plasma], RosePine-Main-BL-LB [GTK2/3] 
      :osssssss/        osssso+++.       Icons: Colloid-grey-dark [Plasma], Colloid-grey-dark [GTK2/3] 
     /ossssssss/        +ssssooo/-       Terminal: tmux 
   `/ossssso+/:-        -:/+osssso+-     CPU: AMD Ryzen 7 4800H with Radeon Graphics (16) @ 2.900GHz 
  `+sso+:-`                 `.-/+oso:    GPU: NVIDIA GeForce GTX 1650 Ti Mobile 
 `++:.                           `-/+/   Memory: 7225MiB / 39983MiB 
 .`                                 `/

❯ inxi -G
Graphics:
  Device-1: NVIDIA TU117M [GeForce GTX 1650 Ti Mobile] driver: nvidia
    v: 535.171.04
  Device-2: IMC Networks Integrated Camera driver: uvcvideo type: USB
  Display: wayland server: X.org v: 1.21.1.12 with: Xwayland v: 23.2.5
    compositor: kwin_wayland driver: X: loaded: nvidia
    unloaded: modesetting,vesa gpu: nvidia resolution: 3840x2160
  API: EGL Message: No EGL data available.
  API: OpenGL v: 4.6.0 vendor: nvidia v: 535.171.04 renderer: NVIDIA
    GeForce GTX 1650 Ti/PCIe/SSE2
  API: Vulkan v: 1.3.279 drivers: nvidia surfaces: xcb,xlib,wayland

❯ cat /sys/class/drm/card0-HDMI-A-1/edid | parse-edid
Checksum Correct

Section "Monitor"
	Identifier "LG TV SSCR2"
	ModelName "LG TV SSCR2"
	VendorName "GSM"
	# Monitor Manufactured week 1 of 2023
	# EDID version 1.3
	# Digital Display
	DisplaySize 1600 900
	Gamma 2.20
	Option "DPMS" "false"
	Horizsync 30-255
	VertRefresh 24-120
	# Maximum pixel clock is 1190MHz
	#Not giving standard mode: 640x480, 60Hz
	#Not giving standard mode: 800x600, 60Hz
	#Not giving standard mode: 1024x768, 60Hz
	#Not giving standard mode: 1152x864, 60Hz
	#Not giving standard mode: 1280x1024, 60Hz
	#Not giving standard mode: 1920x1080, 60Hz

	#Extension block found. Parsing...
#WARNING: I may have missed a mode (CEA mode 97)
#DOUBLE WARNING: It's your first mode, too, so this may actually be important.
#WARNING: I may have missed a mode (CEA mode 96)
#DOUBLE WARNING: It's your first mode, too, so this may actually be important.
#WARNING: I may have missed a mode (CEA mode 118)
#DOUBLE WARNING: It's your first mode, too, so this may actually be important.
#WARNING: I may have missed a mode (CEA mode 117)
#DOUBLE WARNING: It's your first mode, too, so this may actually be important.
#WARNING: I may have missed a mode (CEA mode 102)
#DOUBLE WARNING: It's your first mode, too, so this may actually be important.
#WARNING: I may have missed a mode (CEA mode 101)
#DOUBLE WARNING: It's your first mode, too, so this may actually be important.
#WARNING: I may have missed a mode (CEA mode 91)
#DOUBLE WARNING: It's your first mode, too, so this may actually be important.
#WARNING: I may have missed a mode (CEA mode 90)
#DOUBLE WARNING: It's your first mode, too, so this may actually be important.
#WARNING: I may have missed a mode (CEA mode 93)
#WARNING: I may have missed a mode (CEA mode 94)
#WARNING: I may have missed a mode (CEA mode 95)
#WARNING: I may have missed a mode (CEA mode 98)
#WARNING: I may have missed a mode (CEA mode 99)
#WARNING: I may have missed a mode (CEA mode 100)
#WARNING: I may have missed a mode (CEA mode 63)
#WARNING: I may have missed a mode (CEA mode 64)
	Modeline 	"Mode 2" 148.500 1920 2008 2052 2200 1080 1084 1089 1125 +hsync +vsync
	Modeline 	"Mode 0" +hsync +vsync 
	Modeline 	"Mode 1" +hsync +vsync 
	Modeline 	"Mode 3" 148.500 1920 2448 2492 2640 1080 1084 1089 1125 +hsync +vsync
	Modeline 	"Mode 4" 74.250 1280 1390 1420 1650 720 725 730 750 +hsync +vsync
	Modeline 	"Mode 5" 74.250 1280 1720 1760 1980 720 725 730 750 +hsync +vsync
	Modeline 	"Mode 6" 74.250 1920 2008 2052 2200 1080 1082 1087 1125 +hsync +vsync interlace
	Modeline 	"Mode 7" 74.250 1920 2448 2492 2640 1080 1082 1089 1125 +hsync +vsync interlace
	Modeline 	"Mode 8" 27.027 720 736 798 858 480 489 495 525 -hsync -vsync
	Modeline 	"Mode 9" 27.027 720 736 798 858 480 489 495 525 -hsync -vsync
	Modeline 	"Mode 10" 27.000 720 732 796 864 576 581 586 625 -hsync -vsync
	Modeline 	"Mode 11" 74.250 1920 2558 2602 2750 1080 1084 1089 1125 +hsync +vsync
	Modeline 	"Mode 12" 74.250 1920 2448 2492 2640 1080 1084 1089 1125 +hsync +vsync
	Modeline 	"Mode 13" 74.250 1920 2008 2052 2200 1080 1084 1089 1125 +hsync +vsync
	Modeline 	"Mode 14" 27.000 1440 1464 1590 1728 576 578 581 625 -hsync -vsync interlace
	Option "PreferredMode" "Mode 2"
EndSection

❯ kscreen-doctor -o
Output: 1 HDMI-A-1                                                                                                                                    
        enabled                                                                                                                                       
        connected                                                                                                                                     
        priority 1                                                                                                                                    
        HDMI                                                                                                                                          
        Modes:  0:3840x2160@60*!  1:4096x2160@60  2:4096x2160@50  3:4096x2160@30  4:4096x2160@25  5:4096x2160@24  6:4096x2160@24  7:3840x2160@60  8:38
40x2160@50  9:3840x2160@30  10:3840x2160@25  11:3840x2160@24  12:2560x1440@120  13:1920x1080@120  14:1920x1080@100  15:1920x1080@60  16:1920x1080@60  
17:1920x1080@50  18:1920x1080@30  19:1920x1080@25  20:1920x1080@24  21:1280x1024@60  22:1152x864@60  23:1280x720@60  24:1280x720@50  25:1024x768@60  2
6:800x600@60  27:720x576@50  28:720x480@60  29:640x480@60  30:640x480@60                                                                              
        Scale: 1
        Rotation: 1
        Overscan: 0
        Vrr: Never
        RgbRange: unknown
        HDR: incapable
        Wide Color Gamut: incapable
        ICC profile: none
Output: 2 eDP-1
        disabled
        connected
        priority 0
        Panel
        Modes:  0:1920x1080@60*! 
        Geometry: 3840,0 1920x1080
        Scale: 1
        Rotation: 1
        Overscan: 0
        Vrr: incapable
        RgbRange: unknown
        HDR: incapable
        Wide Color Gamut: incapable
        ICC profile: none

[Edit] It's LG C3, not LG G3.

Last edited by reloadedd (2024-04-29 21:34:02)

seth

Member

Registered: 2012-09-03

Posts: 60,000

Re: [SOLVED] Can't set 4k@120Hz on LG C3

cat /sys/class/drm/card0-HDMI-A-1/edid | parse-edid

Try https://aur.archlinux.org/packages/edid-decode-git

Do the 120Hz show up in an X11 session?
Can you add it there?
https://wiki.archlinux.org/title/Xrandr … esolutions

% cvt12 3840 2160 120
# 3840x2160 @ 120.000 Hz (CVT) field rate 119.976 Hz; hsync: 277.865 kHz; pclk: 1498.25 MHz
Modeline "3840x2160_120.00"  1498.25  3840 4192 4616 5392  2160 2163 2168 2316 -hsync +vsync
%  cvt12 3840 2160 120 -r
# 3840x2160 @ 120.000 Hz Reduced Blank (CVT) field rate 119.999 Hz; hsync: 274.438 kHz; pclk: 1097.75 MHz
Modeline "3840x2160_120.00_rb1"  1097.75  3840 3888 3920 4000  2160 2163 2168 2287 +hsync -vsync
%  cvt12 3840 2160 120 -b
# 3840x2160 @ 120.000 Hz Reduced Blank (CVT) field rate 120.000 Hz; hsync: 274.440 kHz; pclk: 1075.80 MHz
Modeline "3840x2160_120.00_rb2"  1075.80  3840 3848 3880 3920  2160 2273 2281 2287 +hsync -vsync

Probably unrelated, but

dual boot with Windows 11 and they are on separate SSDs

The location doesn't matter - you still need to make sure to disable fast-start (it's NOT the BIOS setting!) and reboot windows and linux twice for voodo reasons to get rid of the impact.
See the 3rd link below.

---

How to upload text · How to boot w/o GUI · Disable Windows Fast-Start! · Fix your xinitrc

reloadedd

Member

Registered: 2023-07-06

Posts: 12

Re: [SOLVED] Can't set 4k@120Hz on LG C3

Hi,

❯ cat /sys/class/drm/card0-HDMI-A-1/edid | edid-decode
edid-decode (hex):

00 ff ff ff ff ff ff 00 1e 6d cd 81 01 01 01 01
01 21 01 03 80 a0 5a 78 0a ee 91 a3 54 4c 99 26
0f 50 54 a1 08 00 31 40 45 40 61 40 71 40 81 80
d1 c0 01 01 01 01 08 e8 00 30 f2 70 5a 80 b0 58
8a 00 40 84 63 00 00 1e 6f c2 00 a0 a0 a0 55 50
30 20 35 00 40 84 63 00 00 1e 00 00 00 fd 00 18
78 1e ff 77 00 0a 20 20 20 20 20 20 00 00 00 fc
00 4c 47 20 54 56 20 53 53 43 52 32 0a 20 01 9d

02 03 6c f1 5d 61 60 76 75 66 65 db da 10 1f 04
13 05 14 03 02 12 20 21 22 15 5d 5e 5f 62 63 64
3f 40 32 09 57 07 15 07 50 57 07 01 3d 1e c0 5f
7e 07 67 04 03 6e 03 0c 00 20 00 b8 44 2c 00 80
01 02 03 04 6d d8 5d c4 01 78 80 6b 43 28 78 d3
33 05 e2 00 cf e3 05 c0 00 e3 06 0d 01 e2 0f ff
eb 01 46 d0 00 48 22 6e 84 60 6e 95 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 8c

----------------

Block 0, Base EDID:
  EDID Structure Version & Revision: 1.3
  Vendor & Product Identification:
    Manufacturer: GSM
    Model: 33229
    Serial Number:  [REDACTED]
    Made in: week 1 of 2023
  Basic Display Parameters & Features:
    Digital display
    Maximum image size: 160 cm x 90 cm
    Gamma: 2.20
    RGB color display
    First detailed timing is the preferred timing
  Color Characteristics:
    Red  : 0.6396, 0.3300
    Green: 0.2998, 0.5996
    Blue : 0.1503, 0.0595
    White: 0.3125, 0.3291
  Established Timings I & II:
    IBM     :   720x400    70.081663 Hz   9:5     31.467 kHz     28.320000 MHz
    DMT 0x04:   640x480    59.940476 Hz   4:3     31.469 kHz     25.175000 MHz
    DMT 0x09:   800x600    60.316541 Hz   4:3     37.879 kHz     40.000000 MHz
    DMT 0x10:  1024x768    60.003840 Hz   4:3     48.363 kHz     65.000000 MHz
  Standard Timings:
    DMT 0x04:   640x480    59.940476 Hz   4:3     31.469 kHz     25.175000 MHz
    DMT 0x09:   800x600    60.316541 Hz   4:3     37.879 kHz     40.000000 MHz
    DMT 0x10:  1024x768    60.003840 Hz   4:3     48.363 kHz     65.000000 MHz
    GTF     :  1152x864    60.000000 Hz   4:3     53.700 kHz     81.624000 MHz
    DMT 0x23:  1280x1024   60.019740 Hz   5:4     63.981 kHz    108.000000 MHz
    DMT 0x52:  1920x1080   60.000000 Hz  16:9     67.500 kHz    148.500000 MHz
  Detailed Timing Descriptors:
    DTD 1:  3840x2160   60.000000 Hz  16:9    135.000 kHz    594.000000 MHz (1600 mm x 900 mm)
                 Hfront  176 Hsync  88 Hback  296 Hpol P
                 Vfront    8 Vsync  10 Vback   72 Vpol P
    DTD 2:  2560x1440  119.997589 Hz  16:9    182.996 kHz    497.750000 MHz (1600 mm x 900 mm)
                 Hfront   48 Hsync  32 Hback   80 Hpol P
                 Vfront    3 Vsync   5 Vback   77 Vpol P
    Display Range Limits:
      Monitor ranges (GTF): 24-120 Hz V, 30-255 kHz H, max dotclock 1190 MHz
    Display Product Name: 'LG TV SSCR2'
  Extension blocks: 1
Checksum: 0x9d

----------------

Block 1, CTA-861 Extension Block:
  Revision: 3
  Underscans IT Video Formats by default
  Basic audio support
  Supports YCbCr 4:4:4
  Supports YCbCr 4:2:2
  Native detailed modes: 1
  Video Data Block:
    VIC  97:  3840x2160   60.000000 Hz  16:9    135.000 kHz    594.000000 MHz
    VIC  96:  3840x2160   50.000000 Hz  16:9    112.500 kHz    594.000000 MHz
    VIC 118:  3840x2160  120.000000 Hz  16:9    270.000 kHz   1188.000000 MHz
    VIC 117:  3840x2160  100.000000 Hz  16:9    225.000 kHz   1188.000000 MHz
    VIC 102:  4096x2160   60.000000 Hz 256:135  135.000 kHz    594.000000 MHz
    VIC 101:  4096x2160   50.000000 Hz 256:135  112.500 kHz    594.000000 MHz
    VIC 219:  4096x2160  120.000000 Hz 256:135  270.000 kHz   1188.000000 MHz
    VIC 218:  4096x2160  100.000000 Hz 256:135  225.000 kHz   1188.000000 MHz
    VIC  16:  1920x1080   60.000000 Hz  16:9     67.500 kHz    148.500000 MHz
    VIC  31:  1920x1080   50.000000 Hz  16:9     56.250 kHz    148.500000 MHz
    VIC   4:  1280x720    60.000000 Hz  16:9     45.000 kHz     74.250000 MHz
    VIC  19:  1280x720    50.000000 Hz  16:9     37.500 kHz     74.250000 MHz
    VIC   5:  1920x1080i  60.000000 Hz  16:9     33.750 kHz     74.250000 MHz
    VIC  20:  1920x1080i  50.000000 Hz  16:9     28.125 kHz     74.250000 MHz
    VIC   3:   720x480    59.940060 Hz  16:9     31.469 kHz     27.000000 MHz
    VIC   2:   720x480    59.940060 Hz   4:3     31.469 kHz     27.000000 MHz
    VIC  18:   720x576    50.000000 Hz  16:9     31.250 kHz     27.000000 MHz
    VIC  32:  1920x1080   24.000000 Hz  16:9     27.000 kHz     74.250000 MHz
    VIC  33:  1920x1080   25.000000 Hz  16:9     28.125 kHz     74.250000 MHz
    VIC  34:  1920x1080   30.000000 Hz  16:9     33.750 kHz     74.250000 MHz
    VIC  21:  1440x576i   50.000000 Hz   4:3     15.625 kHz     27.000000 MHz
    VIC  93:  3840x2160   24.000000 Hz  16:9     54.000 kHz    297.000000 MHz
    VIC  94:  3840x2160   25.000000 Hz  16:9     56.250 kHz    297.000000 MHz
    VIC  95:  3840x2160   30.000000 Hz  16:9     67.500 kHz    297.000000 MHz
    VIC  98:  4096x2160   24.000000 Hz 256:135   54.000 kHz    297.000000 MHz
    VIC  99:  4096x2160   25.000000 Hz 256:135   56.250 kHz    297.000000 MHz
    VIC 100:  4096x2160   30.000000 Hz 256:135   67.500 kHz    297.000000 MHz
    VIC  63:  1920x1080  120.000000 Hz  16:9    135.000 kHz    297.000000 MHz
    VIC  64:  1920x1080  100.000000 Hz  16:9    112.500 kHz    297.000000 MHz
  Audio Data Block:
    Linear PCM:
      Max channels: 2
      Supported sample rates (kHz): 192 96 48 44.1 32
      Supported sample sizes (bits): 24 20 16
    AC-3:
      Max channels: 6
      Supported sample rates (kHz): 48 44.1 32
      Maximum bit rate: 640 kb/s
    Enhanced AC-3 (DD+):
      Max channels: 8
      Supported sample rates (kHz): 48 44.1 32
      Supports Joint Object Coding
    DTS:
      Max channels: 6
      Supported sample rates (kHz): 96 88.2 48 44.1
      Maximum bit rate: 1536 kb/s
    DTS-HD:
      Max channels: 8
      Supported sample rates (kHz): 192 176.4 96 88.2 48 44.1
      Supports DTS:X
      Audio Format Code dependent value: 0x07
    MAT (MLP):
      Max channels: 8
      Supported sample rates (kHz): 48
      Supports Dolby TrueHD, object audio PCM and channel-based PCM
      Hash calculation not required for object audio PCM or channel-based PCM
  Vendor-Specific Data Block (HDMI), OUI 00-0C-03:
    Source physical address: 2.0.0.0
    Supports_AI
    DC_36bit
    DC_30bit
    DC_Y444
    Maximum TMDS clock: 340 MHz
    Supported Content Types:
      Cinema
      Game
    Extended HDMI video details:
      HDMI VICs:
        HDMI VIC 1:  3840x2160   30.000000 Hz  16:9     67.500 kHz    297.000000 MHz
        HDMI VIC 2:  3840x2160   25.000000 Hz  16:9     56.250 kHz    297.000000 MHz
        HDMI VIC 3:  3840x2160   24.000000 Hz  16:9     54.000 kHz    297.000000 MHz
        HDMI VIC 4:  4096x2160   24.000000 Hz 256:135   54.000 kHz    297.000000 MHz
  Vendor-Specific Data Block (HDMI Forum), OUI C4-5D-D8:
    Version: 1
    Maximum TMDS Character Rate: 600 MHz
    SCDC Present
    Max Fixed Rate Link: 3 and 6 Gbps per lane on 3 lanes, 6, 8, 10 and 12 Gbps on 4 lanes
    Supports UHD VIC
    Supports 12-bits/component Deep Color 4:2:0 Pixel Encoding
    Supports 10-bits/component Deep Color 4:2:0 Pixel Encoding
    Supports QMS
    Supports Auto Low-Latency Mode
    Supports a FAPA in blanking after first active video line
    VRRmin: 40 Hz
    VRRmax: 120 Hz
    Supports VESA DSC 1.2a compression
    Supports Compressed Video Transport for 4:2:0 Pixel Encoding
    Supports QMS TFRmin
    Supports 12 bpc Compressed Video Transport
    Supports 10 bpc Compressed Video Transport
    DSC Max Slices: up to 4 slices and up to (340 MHz/Ksliceadjust) pixel clock per slice
    DSC Max Fixed Rate Link: 3 and 6 Gbps per lane on 3 lanes, 6 Gbps on 4 lanes
    Maximum number of bytes in a line of chunks: 6144
  Video Capability Data Block:
    YCbCr quantization: Selectable (via AVI YQ)
    RGB quantization: Selectable (via AVI Q)
    PT scan behavior: No Data
    IT scan behavior: Supports both over- and underscan
    CE scan behavior: Supports both over- and underscan
  Colorimetry Data Block:
    BT2020YCC
    BT2020RGB
  HDR Static Metadata Data Block:
    Electro optical transfer functions:
      Traditional gamma - SDR luminance range
      SMPTE ST2084
      Hybrid Log-Gamma
    Supported static metadata descriptors:
      Static metadata type 1
  YCbCr 4:2:0 Capability Map Data Block:
    VIC  97:  3840x2160   60.000000 Hz  16:9    135.000 kHz    594.000000 MHz
    VIC  96:  3840x2160   50.000000 Hz  16:9    112.500 kHz    594.000000 MHz
    VIC 118:  3840x2160  120.000000 Hz  16:9    270.000 kHz   1188.000000 MHz
    VIC 117:  3840x2160  100.000000 Hz  16:9    225.000 kHz   1188.000000 MHz
    VIC 102:  4096x2160   60.000000 Hz 256:135  135.000 kHz    594.000000 MHz
    VIC 101:  4096x2160   50.000000 Hz 256:135  112.500 kHz    594.000000 MHz
    VIC 219:  4096x2160  120.000000 Hz 256:135  270.000 kHz   1188.000000 MHz
    VIC 218:  4096x2160  100.000000 Hz 256:135  225.000 kHz   1188.000000 MHz
  Vendor-Specific Video Data Block (Dolby), OUI 00-D0-46:
    Version: 2 (12 bytes)
    DM Version: 4.x
    Backlt Min Luma: 75 cd/m^2
    Interface: Standard + Low-Latency
    Supports 10b 12b 444: Not supported
    Target Min PQ v2: 80 (0.00827830 cd/m^2)
    Target Max PQ v2: 2900 (669 cd/m^2)
    Unique Rx, Ry: 0.67578125, 0.32031250
    Unique Gx, Gy: 0.25781250, 0.68750000
    Unique Bx, By: 0.14843750, 0.05078125
Checksum: 0x8c  Unused space in Extension Block: 19 bytes

No, 120Hz does not show up in X11. I've tried adding the resolutions back on Wayland, however nothing happens. kscreen-doctor also does not see the newly added resolution. Here are the steps that I took, for every one of those 3 resolutions:

❯ xrandr --newmode "3840x2160_120.00_rb2"  1075.80  3840 3848 3880 3920  2160 2273 2281 2287 +hsync -vsync
❯ xrandr --addmode HDMI-A-1 3840x2160_120.00_rb2
❯ xrandr --output HDMI-A-1 --mode 3840x2160_120.00_rb2
❯ kscreen-doctor -o
Output: 2 HDMI-A-1
        enabled
        connected
        priority 1
        HDMI
        Modes:  0:3840x2160@60*!  1:4096x2160@60  2:4096x2160@50  3:4096x2160@30  4:4096x2160@25  5:4096x2160@24  6:4096x2160@24  7:3840x2160@60  8:3840x2160@50  9:3840x2160@30  10:3840x2160@25  11:3840x2160@24  12:2560x1440@120  13:1920x1080@120  14:1920x1080@100  15:1920x1080@60  16:1920x1080@60  17:1920x1080@50  18:1920x1080@30  19:1920x1080@25  20:1920x1080@24  21:1280x1024@60  22:1152x864@60  23:1280x720@60  24:1280x720@50  25:1024x768@60  26:800x600@60  27:720x576@50  28:720x480@60  29:640x480@60  30:640x480@60 
        Geometry: 0,0 3840x2160
        Scale: 1
        Rotation: 1
        Overscan: 0
        Vrr: Automatic
        RgbRange: unknown
        HDR: incapable
        Wide Color Gamut: incapable
        ICC profile: none

I'm also seeing a bunch of these warnings in dmesg:

[ 3877.362450] nvidia-modeset: WARNING: GPU:0: BOE Technology Group Co., Ltd (DP-2): G-SYNC Compatible: EDID min refresh rate invalid, disabling G-SYNC Compatible.

Regarding the fast boot, does it have anything to do with the issue at hand? I don't care that much about hibernation, nor do I use it.

seth

Member

Registered: 2012-09-03

Posts: 60,000

Re: [SOLVED] Can't set 4k@120Hz on LG C3

I've tried adding the resolutions back on Wayland, however nothing happens.

You cannot use xrandr on wayland this way.

Detailed Timing Descriptors:
    DTD 1:  3840x2160   60.000000 Hz  16:9    135.000 kHz    594.000000 MHz (1600 mm x 900 mm)
    DTD 2:  2560x1440  119.997589 Hz  16:9    182.996 kHz    497.750000 MHz (1600 mm x 900 mm)

Block 1, CTA-861 Extension Block:
VIC 118:  3840x2160  120.000000 Hz  16:9    270.000 kHz   1188.000000 MHz

  YCbCr 4:2:0 Capability Map Data Block:
    VIC 118:  3840x2160  120.000000 Hz  16:9    270.000 kHz   1188.000000 MHz

Add /etc/X11/xorg.conf.d/20-nvidia.conf

Section "Device"                                                                                                                
    Identifier "GTX1650Ti"                                                                                                          
    Driver  "nvidia"                                                                                                            
    Option  "ModeDebug" "True"
EndSection

(if you already have a config there or, hopefully not, a static server config in /etc/X11/xorg.conf, just inject teh ModeDebug option there) make sure to restart X11 and then please post your Xorg log, https://wiki.archlinux.org/title/Xorg#General

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reloadedd

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Registered: 2023-07-06

Posts: 12

Re: [SOLVED] Can't set 4k@120Hz on LG C3

Since it's too large to upload on PasteBin, I've uploaded the file on Internxt (recommended by Privacy Tools).

You cannot use xrandr on wayland this way.

Okay, tried on X11 then:

❯ xrandr --newmode "3840x2160_120.00"  1501.69  3840 4192 4624 5408  2160 2161 2164 2314  -HSync +Vsync

❯ xrandr --addmode HDMI-0 3840x2160_120.00
X Error of failed request:  BadMatch (invalid parameter attributes)
  Major opcode of failed request:  140 (RANDR)
  Minor opcode of failed request:  18 (RRAddOutputMode)
  Serial number of failed request:  35
  Current serial number in output stream:  36

spiffeeroo

Member

Registered: 2021-04-23

Posts: 23

Re: [SOLVED] Can't set 4k@120Hz on LG C3

Is it possible for the GTX 1650 Ti with HDMI 2.0b ports to output at 4k/120Hz? If I recall correctly, HDMI 2.1 ports were required to get 4k/120Hz.

seth

Member

Registered: 2012-09-03

Posts: 60,000

Re: [SOLVED] Can't set 4k@120Hz on LG C3

http://0x0.st -  there's no sensitive data in your xorg log

There're two outputs

[    13.925] (--) NVIDIA(GPU-0): LG Electronics LG TV SSCR2 (DFP-2): 600.0 MHz maximum pixel clock
[    13.926] (--) NVIDIA(GPU-0): BOE Technology Group Co., Ltd (DFP-3): 2660.0 MHz maximum pixel clock

BOE is your internal display, the LG TV is behind what looks like an (insufficient) HDMI 2.0 connection - the GPU isn't the limitating factor - check the manual of the TV whether it supports HDMI 2.1 in which case it's the cable.

[    13.930] (WW) NVIDIA(GPU-0):   Validating Mode "3840x2160_120":
[    13.930] (WW) NVIDIA(GPU-0):     Mode Source: EDID
[    13.930] (WW) NVIDIA(GPU-0):     3840 x 2160 @ 120 Hz
[    13.930] (WW) NVIDIA(GPU-0):       Pixel Clock      : 1186.81 MHz
[    13.930] (WW) NVIDIA(GPU-0):       HRes, HSyncStart : 3840, 4016
[    13.930] (WW) NVIDIA(GPU-0):       HSyncEnd, HTotal : 4104, 4400
[    13.930] (WW) NVIDIA(GPU-0):       VRes, VSyncStart : 2160, 2168
[    13.930] (WW) NVIDIA(GPU-0):       VSyncEnd, VTotal : 2178, 2250
[    13.930] (WW) NVIDIA(GPU-0):       Sync Polarity    : +H +V 
[    13.930] (WW) NVIDIA(GPU-0):     Mode is rejected: PixelClock (1186.8 MHz) too high for
[    13.930] (WW) NVIDIA(GPU-0):     Display Device (Max: 600.0 MHz).
[    13.930] (WW) NVIDIA(GPU-0):     GPU extended capability check failed.
[    13.930] (WW) NVIDIA(GPU-0):     Mode "3840x2160_120" is invalid.

So the mode gets filtered for that.
I'd take a close look at the cable, ideally use displayport but in doubt you can override this

Option "ModeValidation" "NoMaxPClkCheck, NoEdidMaxPClkCheck"

Or to limit the override to the specific output

Option "ModeValidation" "DFP-2: NoMaxPClkCheck, NoEdidMaxPClkCheck"

but the signal might not be stable (the cable is maybe "on the edge")

Edit: @spiffeeroo are you sure the GPU doesn't do HDMI 2.1??

Last edited by seth (2024-04-25 21:35:58)

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reloadedd

Member

Registered: 2023-07-06

Posts: 12

Re: [SOLVED] Can't set 4k@120Hz on LG C3

Is it possible for the GTX 1650 Ti with HDMI 2.0b ports to output at 4k/120Hz? If I recall correctly, HDMI 2.1 ports were required to get 4k/120Hz.

Yeah... I don't know exactly how I assumed the GTX 1650 Ti has HDMI 2.1, but it doesn't... See Specs -> VIEW FULL SPECS. They started to add HDMI 2.1 support starting with RTX 30 Series.

BOE is your internal display, the LG TV is behind what looks like an (insufficient) HDMI 2.0 connection - the GPU isn't the limitating factor - check the manual of the TV whether it supports HDMI 2.1 in which case it's the cable.

The GPU is the issue, specifically the HDMI 2.0b port. See also the laptop specs. The TV has 4 HDMI ports and all of them are HDMI 2.1.

I was distracted by Windows running on 4K @ 120 Hz, however after more reading on the subject, I found out that Windows is using 4:2:0 chroma for making that happen. That begs the next questions, how can I do the same on Linux, Wayland specifically? I want to use 4:2:0 chroma and 4K @ 120. I prefer more the smoothness rather than picture quality.

seth

Member

Registered: 2012-09-03

Posts: 60,000

Re: [SOLVED] Can't set 4k@120Hz on LG C3

Does

Option "ColorSpace" "YCbCr420"

work?
According to the documention the mode should™ be autoselected, but apparently only for 60Hz?

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reloadedd

Member

Registered: 2023-07-06

Posts: 12

Re: [SOLVED] Can't set 4k@120Hz on LG C3

Nope, doesn't work. This is the config that I've used:

❯ cat /etc/X11/xorg.conf.d/20-nvidia.conf 
Section "Device"
    Identifier "GTX1650Ti"
    Driver "nvidia"
    Option "ModeDebug" "True"
    Option "ModeValidation" "NoMaxPClkCheck, NoEdidMaxPClkCheck, NoEdidHDMI2Check"
    Option "ColorSpace" "YCbCr420"
EndSection

I'm also seeing this in Xorg log:

        "Default Screen Section" for depth/fbbpp 24/32
[    13.334] (==) NVIDIA(0): Depth 24, (==) framebuffer bpp 32
[    13.334] (==) NVIDIA(0): RGB weight 888
[    13.334] (==) NVIDIA(0): Default visual is TrueColor
[    13.334] (==) NVIDIA(0): Using gamma correction (1.0, 1.0, 1.0)
[    13.334] (II) Applying OutputClass "nvidia" options to /dev/dri/card0
[    13.334] (**) NVIDIA(0): Option "ColorSpace" "YCbCr420"
[    13.334] (**) NVIDIA(0): Option "ModeValidation" "NoMaxPClkCheck, NoEdidMaxPClkCheck, NoEdidHDMI2Check"
[    13.334] (**) NVIDIA(0): Option "ModeDebug" "True"
[    13.334] (**) NVIDIA(0): Option "AllowEmptyInitialConfiguration"
[    13.334] (WW) NVIDIA(0): Unrecognized ColorSpace token "YCbCr420"; ignoring.

seth

Member

Registered: 2012-09-03

Posts: 60,000

Re: [SOLVED] Can't set 4k@120Hz on LG C3

ideally use displayport

The mode is filtered despite the ModeValidation config??

You could check the monitor and X server display settings in "nvidia-settings"… :\
"ColorSpace" will proably accept "YCbCr444", but I'm not sure that's gonna help you.

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reloadedd

Member

Registered: 2023-07-06

Posts: 12

Re: [SOLVED] Can't set 4k@120Hz on LG C3

ideally use displayport

Sadly, the TV does not have a DisplayPort.

The mode is filtered despite the ModeValidation config??

Looking at the Xorg logs, there were invalid modes, including 3840x2160@120, and, of course, 120 Hz didn't showed up as an option. If you need the logs, I can try to reproduce. Right now, probably because of me messing with the config from the Nvidia settings, the log is smaller and no mention of modes (maybe debug mode is turned off).

Tinkering with nvidia-settings didn't solve much, or anything at all. I tried combining the Color Space & Color Range options, however, to no avail. One the other hand, I've managed to set 120 Hz @ 4K (finally!) using by forcing YUV420 with nvidia-xconfig:

❯ nvidia-xconfig --force-yuv-420

After running the command, the 100 & 120Hz options showed up in Display Configuration. It looks pretty awful especially text, but it is what it is.

Now, how do I force YUV420 on Wayland?

seth

Member

Registered: 2012-09-03

Posts: 60,000

Re: [SOLVED] Can't set 4k@120Hz on LG C3

Now, how do I force YUV420 on Wayland?

Probably "not" - the wayland compositor is the display server and it would have to be able to replicate whatever the nvidia DDX driver is telling the kernel module there.

Do you actually want to?
How awful does it look? Worse than on windows? Do you have a screenhot/photo?
Does the awfulness show on screenshots or is it only on the monitor?

Does it work (and look better?) if you remove the static server config and only add w/ 20-nvidia.conf ?

Section "Device"
    Identifier "GTX1650Ti"
    Driver "nvidia"
#    Option "ModeDebug" "True"
#    Option "ModeValidation" "NoMaxPClkCheck, NoEdidMaxPClkCheck, NoEdidHDMI2Check"
    Option "ForceYUV420" "True"
EndSection

(I'm gonna exploit you a bit since this is completely undocumented upstream and probably should go into the wiki - also the static server config produced by nvidia-xconfig is horrible cruft)

Do the dithering settings (and 6bpp instead of 8bpp) have any impact on the look?

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cajual

Member

Registered: 2024-04-27

Posts: 1

Re: [SOLVED] Can't set 4k@120Hz on LG C3

What is the output of

cat /etc/kernel/cmdline

Try enabling the following at the end of the line:

... nvidia-drm.modeset=1 nvidia-drm.fbdev=1 nvidia-modeset.hdmi_deepcolor=1

This (deepcolor) fixed 4k@120 w/ 10-bit RGB on my C2 (in Wayland, X is stuck in 8-bit RGB, don't use chroma subsampling [402/422/444])

Edit: you need 545+ for this to work, ideally use 550.

Last edited by cajual (2024-04-27 14:03:23)

reloadedd

Member

Registered: 2023-07-06

Posts: 12

Re: [SOLVED] Can't set 4k@120Hz on LG C3

Sorry for the slightly delayed reply, I took some time for testing and also took some pictures.

Do you actually want to?

Hmm, not a strong yes, but it would be nice to have that on Wayland if I decide that I want smoothness. I was using primarily Wayland for enough time to forget that X11 was also installed (performance seems better on Wayland and for some reason, the animations don't work at all on X11, but I don't know if I care that much since I don't plan on using X11). But I can probably live some time until I will change my laptop with one that has HDMI 2.1.

How awful does it look? Worse than on windows? Do you have a screenhot/photo?
Does the awfulness show on screenshots or is it only on the monitor?

Okay, maybe I was exaggerating a bit there. It's not "that" awful. Picture quality is good when looking at videos, the text is the awful bit here. I think it looks the same as on Windows. The awfulness is only on the monitor, screenshots are fine.

Does it work (and look better?) if you remove the static server config and only add w/ 20-nvidia.conf ?
Do the dithering settings (and 6bpp instead of 8bpp) have any impact on the look?

No, it looks the same if I remove the static server config. And no, dithering does not have any effect to me visually using any combination of options.

(I'm gonna exploit you a bit since this is completely undocumented upstream and probably should go into the wiki - also the static server config produced by nvidia-xconfig is horrible cruft)

Glad to be part of the history:)

This (deepcolor) fixed 4k@120 w/ 10-bit RGB on my C2 (in Wayland, X is stuck in 8-bit RGB, don't use chroma subsampling [402/422/444])

That's good to know, however it won't work in my case because of the HDMI 2.0b, which makes impossible to achieve 4k@120 w/ 10-bit RGB given the bandwidth However, I set the kernel parameters (I'm using GRUB) and nothing happened on X11 or Wayland (and yes, I've updated GRUB afterwards). Those are my kernel parameters as of right now:

GRUB_CMDLINE_LINUX_DEFAULT="loglevel=3 quiet nvidia-drm.modeset=1 acpi_backlight=native nvidia-drm.fbdev=1 nvidia-modeset.hdmi_deepcolor=1" 

I have created a folder with pictures, which can be downloaded from 0x0.st. Most of them are HEIC files which can be opened with Gwenview and an add-on whose name I don't remember right now. They also have descriptive names. I have also blurred some of them because of the glossy display doxxing me. One weird thing on X11 is that my screen is turning green when enabling Night Light (see night_light_on_X11.png). The pictures also show text fringing, and it's especially worse on red text over black background. But I think it's equally bad on Windows, therefore it's fine.

Having said that, my problem is mostly solved (in the sense that I can't run at 4K@120 with 10-bit RGB given the missing hardware). The only thing left is maybe forcing the YUV420 on Wayland (I think I would choose to run it on Wayland if I would have the option to), if it's even possible as of right now. Other than that, I'm happy to further help with any questions/testing.

Last edited by reloadedd (2024-04-28 16:33:33)

seth

Member

Registered: 2012-09-03

Posts: 60,000

Re: [SOLVED] Can't set 4k@120Hz on LG C3

https://forums.developer.nvidia.com/t/w … ase/214275

The following workstation features are not supported by any Wayland
compositors or the Wayland protocol. They will also likely require new
EGL extensions or other means to expose the related hardware
functionality.
…
Advanced display pipeline features including warp and blend, pixel shift,
and emulated YUV420.

Looks bleak…

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reloadedd

Member

Registered: 2023-07-06

Posts: 12

Re: [SOLVED] Can't set 4k@120Hz on LG C3

Okay, so it's not supported yet on Wayland. Thanks for the reference.

Looks bleak…

Yeah, but it looks equally bleak on Windows . But if you ask me, the colors are not that bad, text is bad. The tiger picture (video_picture_quality_Linux_X11.HEIC) looks colorful and vivid both in real life and in photo, to me.

Last edited by reloadedd (2024-04-29 20:20:08)

seth

Member

Registered: 2012-09-03

Posts: 60,000

Re: [SOLVED] Can't set 4k@120Hz on LG C3

No, I meant "bleak" wrt the wayland situation

Please always remember to mark resolved threads by editing your initial posts subject - so others will know that there's no task left, but maybe a solution to find.
Thanks. Also for bringing up and confirming the undocumented X11 parameter.

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