Linux driver not setting refresh to monitor maximum while possible in Win11

[SF_B]

A couple of months ago I posted a question here when using a Dell Inspiron 3210 laptop that I could not set the refresh rate to the external monitor's maximum of 75Hz on either Win11 or Linux (Manjaro) when using USB-C to USB-C with Displayport Alt Mode.

This question was "solved" by stating that Dell somehow applied a limitation the Intel Xe iGPU, though I did not find the solution credible. I sold the laptop and got another one, this time an Asus Zenbook UX3405MA-P239W. This laptop is newer and features an Intel Core Ultra 7 155H CPU and an Intel Arc 8C 2.25 Ghz iGPU.

With this laptop the "symptoms" are different as in Win11 the external monitor can be set to the maximum of 75Hz without issues out of the box. (I am dual booting Win11/Manjaro)

The issue remains with Linux, however. I can only set the external monitor to 3840x1600 at 60Hz maximum. I've included the edid information as text as well as binary for you to test.

In this case, as it works in Windows, I don't see it being a vendor limitation but a driver issue for sure.

The question is: how can I set the maximum refresh rate of the external monitor? I have tried the i915 and the xe driver. Happens with both. Currently I am running the xe driver.

Thank you.

[JeanetteC_Intel]

Hello SF_B,

Thank you for posting in Intel Communities.

I would like to know more about your system details to fully understand where the issue truly lies. Please provide the missing key information below:

• Which Linux distribution and version are you using?
• Kindly share your system configuration so I can fully check and provide you with an accurate fix. This could be possible by downloading the Intel® System Support Utility for the Linux* Operating System.

1. Download the Intel® System Support Utility for the Linux* operating system and save the ssu.tar.gz file to your system.
2. Extract the ssu.sh file from ssu.tar.gz and save to your system.
3. To run the ssu.sh script from a Linux* terminal, Open Applications->Accessories->Terminal.
4. From the current directory, navigate to the current folder where the ssu.sh file resides. For example, if you saved the ssu.sh file to a folder called SSU File, the command would be cd SSU File.
5. Run the ssu.sh file using this command: ./ssu.sh <parameter=0|1> where 0 = off and 1 = enabled.
6. Use the parameter definitions included in the readme to determine which parameter to use.

• Note:
• If no parameter is specified and only ./ssu.sh is run, it captures all system information with the exception of 3rd party logs that must be specified.

I look forward to your response.

Best regards,

JeanetteC.

Intel® Customer Support Technician

[SF_B]

Thank you Jeanette! I will do this soon and also on the Win11 side so you can compare.

[SF_B]

So it seems the Linux SSU has been removed from the downloads section... 3 months ago I could still find it there. But I also remember that the information output of the SSU was rather limited. Maybe you can provide a direct link to the downloadable file or the file itself here?

[JeanetteC_Intel]

Hello SF_B,

Thank you for bringing this to our attention regarding the Linux SSU tool. You're correct that it's no longer available in our downloads section. I'm unable to provide direct links or attachments at this time, but I'll look into this and follow up with you once I have details.

Best regards,

JeanetteC.

Intel Customer Support Technician

[JeanetteC_Intel]

Hello SF_B,

Please be advised that I am still currently looking into this issue you've raised. To move forward with the troubleshooting process, I'll need the following information:

1. Current kernel driver version for your Intel® Arc™ graphics

• Please refer to: How to Identify &amp; Find Graphics Drivers for Linux*

1. Intel SSU report for Windows - please run the tool and share the log file
2. Do you know which specific Linux driver is affected?
3. Regarding the USB-C to USB-C with DisplayPort Alt Mode connection - can you confirm this is a direct connection without any adapters?
4. External monitor details - exact make, model, and specifications page (if available)

This information will help me provide you with the most accurate solution.

Looking forward to your response.

Best regards,

JeanetteC.

Intel Customer Support Technician

[SF_B]

I am using Manjaro (arch-based distro) with kernel 6.12.44-3. But I checked and it also happens on the newest Ubuntu (25.04) or Debian 13 which use older kernels.

1) Output of "lspci -k | grep -EA3 'VGA|3D|Display'":

0000:00:02.0 VGA compatible controller: Intel Corporation Meteor Lake-P [Intel Arc Graphics] (rev 08)
        DeviceName: VGA
        Subsystem: ASUSTeK Computer Inc. Device 1a63
        Kernel driver in use: xe
        Kernel modules: i915, xe

Win11 SSU coming soon.

2) both drivers, i915 and xe. xe is currently in use.

3) It's a direct connection. I tried different cables, too, but that's not an issue as it works on Win11.

4) The monitor is a 38" ultrawide Acer CB382CURbmiiphuzx. Specs: https://www.displayspecifications.com/en/model/fbce28cc

Further info: Using an USB-C to Displayport cable, I get 75Hz on the monitor. Using a monitor that can go up to 120Hz, I can use USB-C to USB-C DP Alt Mode just fine and get 120Hz. It seems 75Hz is kind of an odd in-between frequency that causes an issue when using DP Alt Mode over USB-C.

[SF_B]

This is the log file generated by the Win11 SSU.

[JeanetteC_Intel]

Hello SF_B,

Thank you for the detailed information and thorough testing across multiple distributions. This helps narrow down the issue significantly. I will proceed with the further investigation of this issue and will share an update once it is available.

Best regards,

JeanetteC.

Intel Customer Support Technician

[JeanetteC_Intel]

Hello SF_B,

After reviewing the information you provided, I found the official support documentation here: Installing Client GPUs — Intel® software for general purpose GPU capabilities documentation. Since you're using Manjaro, I recommend contacting the distribution developers for the appropriate installation commands for Intel graphics drivers on Linux.

I hope this helps.

Sincerely,

JeanetteC.

Intel Customer Support Technician

[SF_B]

Hi, this does not help. I can however test an installation of Ubuntu on this laptop with these drivers and see if it works next week.

Please note that i915 or xe are drivers already and I don't fully understand why Ubuntu has additional drivers.

[JeanetteC_Intel]

Hello SF_B,

Understood. Please move forward with the testing and let me know how it goes. I

Looking forward to your update.

Best regards,

JeanetteC.

Intel Customer Support Technician

[SF_B]

I installed Ubuntu and the Ubuntu-specific Intel drivers. It did not change anything.

I'm beginning to think this is a Linux kernel issue as I got my hands on an AMD based laptop and the same issue occurs. It can't be the monitor as it works with Win 11 and MacOS.

Seems deep down, the "odd" refresh rate of 75Hz over Displayport Alt mode USB-C to USB-C is not supported. I tested with a USB-C to DP cable and it got 75Hz immediately again. I will stick to having to connect two cables instead of one - but this bug is certainly annoying as hell.