I’ve recently switched to Fedora 42 (KDE) to use alongside my Windows 11 dual boot for work after having some previous experience with Ubuntu. Everything has been pretty seamless but I have a minor snag which limits my primary monitor (AW3423DWF) to 100Hz at 3440x1440 when in Windows 11 and Ubuntu 24.04 it can go up to the stated max of 165Hz. I have two other monitors (2560x1440 @ 165Hz) and (1920x1080 @ 75Hz) which all work as required.
I haven’t been able to work out why the 165Hz option is not available so would appreciate any suggested fixes.
I was able to get the 165Hz option to show in Display Configuration using
sudo grubby --update-kernel=ALL --args="amdgpu.dc=1 amdgpu.deep_color=0"
but when it was selected the screen blacked out for a couple of seconds before returning to the default options without the 165Hz option.
Any help would be greatly appreciated!
System info: Radeon 6700XT, Fedora 42, Wayland, KDE Plasma.
pg-tips
October 23, 2025, 8:20pm
2
Is the monitor connected using HDMI or DP?
Some monitors only support the high refresh over a DP cable as there are bandwidth limits on HDMI.
What is the output of kscreen-doctor -o?
It is using a DP1.4 port and cable which work fine in Windows 11. Here is the relevant output for the monitor.
Output: 1 DP-1 154c7706-19f5-499e-84a6-ec2ede18a395
enabled
connected
priority 1
DisplayPort
replication source:0
Modes: 1:3440x1440@60! 2:3440x1440@100* 3:2560x1440@144 4:2560x1440@120 5:2560x1440@60 6:1920x1200@60 7:1920x1080@144 8:1920x1080@120 9:1920x1080@120 10:1920x1080@60 11:1920x1080@60 12:1920x1080@60 13:1920x1080@50 14:1920x1080@30 15:1920x1080@30 16:1920x1080@25 17:1920x1080@24 18:1920x1080@24 19:1600x1200@60 20:1680x1050@60 21:1600x900@60 22:1280x1024@75 23:1280x1024@60 24:1440x900@60 25:1280x800@60 26:1152x864@75 27:1280x720@60 28:1280x720@60 29:1280x720@50 30:1024x768@75 31:1024x768@60 32:800x600@75 33:800x600@60 34:720x576@50 35:720x480@60 36:720x480@60 37:720x480@60 38:720x480@60 39:640x480@75 40:640x480@60 41:640x480@60 42:640x480@60 43:720x400@70 44:1600x1200@100 45:1280x1024@100 46:1024x768@100 47:1920x1200@100 48:1280x800@100 49:2560x1440@100 50:1920x1080@100 51:1600x900@100 52:1368x768@60 53:1368x768@100 54:1280x720@100
Geometry: 2560,373 3440x1440
Scale: 1
Rotation: 1
Overscan: 0
Vrr: Never
RgbRange: Full
HDR: disabled
Wide Color Gamut: disabled
ICC profile: none
Color profile source: sRGB
Color power preference: prefer efficiency and performance
Brightness control: unsupported
DDC/CI: allowed
Color resolution: 8 bits per color, range: [8; 16] bits per color
Allow EDR: unsupported
The Color Depth is set to 8bit which is the only other thing I could think would limit the refresh rate.
barryascott
October 24, 2025, 10:59am
5
As you can see freom the kscreen-doctor output the monitor claims for 144Hz you need to be in 2560x1440@144.
That will be what the monitor EDID is reporting to the system.
If windows allows higher then it is overriding the limits that the monitor reports.
Edit: Or it is a limit of the GPU.
please post the decoded EDID table of this monitor.
something like this:
ls -l /sys/devices/drm/*/edid
edid-decode /path/to/output/DP1/edid # see previous ls output
It works fine on Windows 11 at 165Hz using the same ports and cable and my Radeon drivers are up to date. 165Hz isn’t considered an overclock by the manufacturer as well which is why I’m stumped.
Here is the EDID output: note that in Block 2, DisplayID Extension Block the 3440x1440p @ 164.9Hz is listed.
The paths that contain this EDID file are as follows:
/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/0000:09:00.0/0000:0a:00.0/drm/card1/card1-DP-1/edid
/sys/class/drm/card1-DP-1/
Block 0, Base EDID:
EDID Structure Version & Revision: 1.4
Vendor & Product Identification:
Manufacturer: DEL
Model: 41490
Serial Number: 809710163 (0x30433253)
Made in: week 52 of 2023
Basic Display Parameters & Features:
Digital display
Bits per primary color channel: 10
DisplayPort interface
Maximum image size: 80 cm x 34 cm
Gamma: 2.20
DPMS levels: Off
Supported color formats: RGB 4:4:4, YCrCb 4:4:4, YCrCb 4:2:2
First detailed timing includes the native pixel format and preferred refresh rate
Display supports continuous frequencies
Color Characteristics:
Red : 0.7070, 0.2841
Green: 0.2451, 0.7158
Blue : 0.1464, 0.0527
White: 0.3125, 0.3281
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 0x06: 640x480 75.000000 Hz 4:3 37.500 kHz 31.500000 MHz
DMT 0x09: 800x600 60.316541 Hz 4:3 37.879 kHz 40.000000 MHz
DMT 0x0b: 800x600 75.000000 Hz 4:3 46.875 kHz 49.500000 MHz
DMT 0x10: 1024x768 60.003840 Hz 4:3 48.363 kHz 65.000000 MHz
DMT 0x12: 1024x768 75.028582 Hz 4:3 60.023 kHz 78.750000 MHz
DMT 0x24: 1280x1024 75.024675 Hz 5:4 79.976 kHz 135.000000 MHz
Standard Timings:
DMT 0x15: 1152x864 75.000000 Hz 4:3 67.500 kHz 108.000000 MHz
DMT 0x23: 1280x1024 60.019740 Hz 5:4 63.981 kHz 108.000000 MHz
DMT 0x53: 1600x900 60.000000 Hz 16:9 60.000 kHz 108.000000 MHz (RB)
DMT 0x52: 1920x1080 60.000000 Hz 16:9 67.500 kHz 148.500000 MHz
Detailed Timing Descriptors:
DTD 1: 3440x1440 59.972616 Hz 43:18 88.819 kHz 319.750000 MHz (800 mm x 337 mm)
Hfront 48 Hsync 32 Hback 80 Hpol P
Vfront 3 Vsync 10 Vback 28 Vpol N
Display Product Serial Number: '5XYC2S3'
Display Product Name: 'AW3423DWF'
Display Range Limits:
Monitor ranges (Range Limits Only): 48-165 Hz V, 285-285 kHz H, max dotclock 1020 MHz
Extension blocks: 2
Checksum: 0xee
----------------
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 63: 1920x1080 120.000000 Hz 16:9 135.000 kHz 297.000000 MHz
VIC 34: 1920x1080 30.000000 Hz 16:9 33.750 kHz 74.250000 MHz
VIC 33: 1920x1080 25.000000 Hz 16:9 28.125 kHz 74.250000 MHz
VIC 32: 1920x1080 24.000000 Hz 16:9 27.000 kHz 74.250000 MHz
VIC 31: 1920x1080 50.000000 Hz 16:9 56.250 kHz 148.500000 MHz
VIC 19: 1280x720 50.000000 Hz 16:9 37.500 kHz 74.250000 MHz
VIC 18: 720x576 50.000000 Hz 16:9 31.250 kHz 27.000000 MHz
VIC 16: 1920x1080 60.000000 Hz 16:9 67.500 kHz 148.500000 MHz
VIC 4: 1280x720 60.000000 Hz 16:9 45.000 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 1: 640x480 59.940476 Hz 4:3 31.469 kHz 25.175000 MHz
Audio Data Block:
Linear PCM:
Max channels: 2
Supported sample rates (kHz): 48 44.1 32
Supported sample sizes (bits): 24 20 16
Speaker Allocation Data Block:
FL/FR - Front Left/Right
Colorimetry Data Block:
xvYCC601
xvYCC709
BT2020YCC
BT2020RGB
Gamut Boundary Description Metadata Profile P0
HDR Static Metadata Data Block:
Electro optical transfer functions:
Traditional gamma - SDR luminance range
SMPTE ST2084
Supported static metadata descriptors:
Static metadata type 1
Desired content max luminance: 102 (455.515 cd/m^2)
Desired content max frame-average luminance: 77 (265.047 cd/m^2)
Desired content min luminance: 2 (0.000 cd/m^2)
Vendor-Specific Data Block (AMD), OUI 00-00-1A:
Version: 3
Feature Caps: 0x03
Minimum Refresh Rate: 48 Hz
Maximum Refresh Rate: 165 Hz
Flags 1.x: 0x00
Flags 2.x: 0x84
Maximum luminance: 102 (455.515 cd/m^2)
Minimum luminance: 2 (0.000 cd/m^2)
Maximum luminance (without local dimming): 77 (265.047 cd/m^2)
Minimum luminance (without local dimming): 3 (0.000 cd/m^2)
Video Capability Data Block:
YCbCr quantization: Selectable (via AVI YQ)
RGB quantization: Selectable (via AVI Q)
PT scan behavior: Always Underscanned
IT scan behavior: Always Underscanned
CE scan behavior: Always Underscanned
Detailed Timing Descriptors:
DTD 2: 2560x1440 119.997589 Hz 16:9 182.996 kHz 497.750000 MHz (800 mm x 337 mm)
Hfront 48 Hsync 32 Hback 80 Hpol P
Vfront 3 Vsync 5 Vback 77 Vpol N
DTD 3: 2560x1440 143.973257 Hz 16:9 222.151 kHz 604.250000 MHz (800 mm x 337 mm)
Hfront 48 Hsync 32 Hback 80 Hpol P
Vfront 3 Vsync 5 Vback 95 Vpol N
DTD 4: 3440x1440 99.982172 Hz 43:18 150.973 kHz 538.370000 MHz (800 mm x 337 mm)
Hfront 14 Hsync 32 Hback 80 Hpol P
Vfront 3 Vsync 10 Vback 57 Vpol N
Checksum: 0x64 Unused space in Extension Block: 15 bytes
----------------
Block 2, DisplayID Extension Block:
Version: 1.2
Extension Count: 0
Display Product Type: Standalone display device
Video Timing Modes Type 1 - Detailed Timings Data Block:
DTD: 1920x1080 143.847177 Hz 16:9 162.260 kHz 337.500000 MHz (aspect 16:9, no 3D stereo)
Hfront 48 Hsync 32 Hback 80 Hpol P
Vfront 3 Vsync 5 Vback 40 Vpol N
DTD: 2560x1440 59.950550 Hz 16:9 88.787 kHz 241.500000 MHz (aspect 16:9, no 3D stereo)
Hfront 48 Hsync 32 Hback 80 Hpol P
Vfront 3 Vsync 5 Vback 33 Vpol N
DTD: 3440x1440 164.900019 Hz 16:9 283.133 kHz 1019.280000 MHz (aspect 16:9, no 3D stereo)
Hfront 48 Hsync 32 Hback 80 Hpol P
Vfront 3 Vsync 10 Vback 264 Vpol N
Checksum: 0x0e
Checksum: 0x90
Odd, kscreen-doctor lists all DTDs but the last one. KDE_win bug?release candidate and see if 4k@165hz is available?
You could try to create a custom EDID file and swap 3440x1440@165 with 1920x1080@144. Install wxEDID (flatpak ) and load a copy of the binary EDID file.