ASUS VG279QM does not work at 280 Hz

Technical Issues
1

I can’t get 280 Hz to work on Mabox. I get configure crtc 0 failed. For some reason, Archcraft does not have this problem. Here is someone with the same problem:

https://old.reddit.com/r/linux_gaming/comments/troe12/asus_vg279qm_wont_do_280hz_on_linux/i2mgv79

2

Disclaimer

Note: This guide was created with care, but I have no technical expertise and do not take any responsibility for possible errors or damage resulting from following these instructions. Use at your own risk.

:desktop_computer: Goal

Make your ASUS VG279QM monitor run at 280 Hz on Manjaro Mabox, instead of being stuck at 240 Hz or lower.

:magnifying_glass_tilted_left: Problem Summary

Linux (specifically the kernel) does not trust the 280 Hz mode by default because:

  • It’s an overclocked mode.

  • It’s not listed in the monitor’s base EDID.

  • The kernel says: “:cross_mark: Nope. Not safe. Not using it.”

So even if you try to set it manually, you get:

configure crtc 0 failed

:white_check_mark: Step-by-Step Solution

Step 1: Confirm you are using DisplayPort

:red_exclamation_mark: 280 Hz only works via DisplayPort, not HDMI.

Open terminal and run:

xrandr

Look for something like:

DP-1 connected 1920x1080+0+0 ...

That means you’re using DisplayPort (good!).
If it says HDMI-1, you need to switch the cable to DisplayPort.

Step 2: Check your kernel version

Run:

uname -r

You want something new like 6.8.x or higher.

If it’s older (like 6.1.x), update to the latest LTS:

sudo mhwd-kernel -i linux69

Reboot and check again:

uname -r

Step 3: Try setting the refresh rate with xrandr

This may not work yet, but let’s try.

Run:

cvt 1920 1080 280

You’ll get something like:

# 1920x1080 279.96 Hz (CVT)
Modeline "1920x1080_280.00"  859.25  1920 2080 2288 2656  1080 1083 1088 1160 -hsync +vsync

Now run the following commands (replace with your values):

xrandr --newmode "1920x1080_280.00"  859.25  1920 2080 2288 2656  1080 1083 1088 1160 -hsync +vsync
xrandr --addmode DP-1 "1920x1080_280.00"
xrandr --output DP-1 --mode "1920x1080_280.00"

:warning: If you get configure crtc 0 failed, continue to the next step.

Step 4: Add amdgpu.dc=0 to GRUB (AMD GPUs only)

If you’re using an AMD graphics card, try this:

  1. Open GRUB config:
sudo nano /etc/default/grub
  1. Find the line:
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

Change it to:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash amdgpu.dc=0"

  1. Save and exit (Ctrl+O, Enter, Ctrl+X)

  2. Update GRUB:

sudo update-grub
  1. Reboot:
reboot

After rebooting, try the xrandr commands again.

Step 5: (Optional) Try a newer kernel or EDID override

If nothing works:

  • Try kernel linux69 or linux-mm using mhwd-kernel

  • Ask for help with EDID override (advanced users only)

Most users succeed after setting amdgpu.dc=0 or updating the kernel.

:white_check_mark: Summary Table

Step Description
1 Use DisplayPort, not HDMI
2 Update to a new kernel
3 Try setting 280 Hz via xrandr
4 Add amdgpu.dc=0 to GRUB (AMD only)
5 Try EDID override (optional, advanced)
1 Like
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Step 1: Confirm you are using DisplayPort

Do you think I’m too stupid to know whether I’m using DisplayPort or not?

Step 3: Try setting the refresh rate with xrandr

You want me to try the same thing as what I already did? That’s the definition of insanity.

Step 4: Add amdgpu.dc=0 to GRUB (AMD GPUs only)

If you asked ChatGPT what amdgpu.dc=0 does, it would inform you that’s it’s important for high refresh rate and modern kernels and GPUs. Since I’m using 280 Hz, I’m obviously on a modern GPU. Disabling amdgpu.dc broke my system and I had to manually edit /boot/grub/grub.cfg on another drive. Why couldn’t I edit /etc/default/grub? Because I can’t run update-grub from another hard drive, because I couldn’t run chroot because MABOX DOESN’T HAVE ZSH. I hope we learned an important lesson to question the nonsense ChatGPT spouts since it’s an INANIMATE COMPUTER that can MAKE SHIT UP.

4

Why shout here? Nothing is lost, reverse this change is quite simple. During boot press Esc key to enter grub menu, then press e to edit entry, remove amdgpu.dc=0 and you should boot normally. And of course after that fix this in /etc/default/grub :wink:

I agree, using AI everywhere without at least basic checking is bad idea - both of you should notice that advices from @muzqs and link (from here we know that probably none of these things works) are identical:

@ArchcraftHater please provide basic informations about your system, output of inxy -Fazy should be sufficient for start.

1 Like
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Also, @ArchcraftHater, we are all trying to help here, if the solution doesn’t work or you already tried, just say so without being rude.