Intel arc b580 limits the display refresh rate to 60Hz when setting colour depth to 12 bit

[Doddsey]

I don't know if this is intended as i don't know much about displays but when i go to advanced graphic settings on windows on a colour depth of 12 its limited to 60Hz. If its set to 10 bit its limited to 75Hz. However when at 8 bit colour depth i can go 100Hz. I know its not a big difference but for me its very noticeable when at 60Hz compared to 100Hz. I don't know if the GPU doesn't have enough power to output 12 bit colour at 100Hz+ but i would expect it as its a very capable GPU. I am using HDMI however but the monitors resolution is 1080p so i don't think HDMI is the problem but it could be. This could be intentional for every graphics card as i said I'm not that good at displays and colour depth/bit. When i was on arch Linux i could do 100Hz 12 bit colour i think this is off the top of my head so i could be wrong or inaccurate.

Thanks Doddsey

Below are some screenshots and the spec of my PC

Mobo: Aorus elite b550 ax 

CPU: Ryzen 7 5800x

Ram:32gb  ddr4

GPU: Arc b580 LE

OS: Win 10 pro

Display: Random acer one that can do 100Hz 

[ArchieD_Intel]

Hi Doddsey,

Thank you for reaching out to the Intel Community Forum. To assist us in investigating the issue, please provide the following details:

• Is this working fine before?
• Are you using HDMI 2.0 or higher?
• Have you tried using Display Port?
• Have you tried updating your graphics drivers?

Additionally, to gain a comprehensive understanding of your system, please use the System Support Utility (SSU). This tool will generate a text file compiling all your system information. You can follow the instructions at this link and send the text file here. Help Guide for the Intel® System Support Utility.

If you have any questions, please let us know. Thank you.

Best regards,

Archie D.

Intel Customer Support Technician

[Doddsey]

Hi Archie
I can't recall whether it worked before on windows as it has been a long time since I last used it. But I noticed the refresh rate was limited by the colour depth. As I said it's fine on Linux.

I am using 2.0 HDMI lead.

My monitor doesn't support Display Port.

Drivers are at the latest version.

Is this SSU a separate download?

My monitor only supports 1920x1080 @100Hz so that could be the problem.

[MUC]

Acer KB272 E

1 x HDMI 1.4

I assume that with an HDMI 1.4 connection (under Windows), the link is limited to a pixel clock of 300 MHz TMDS. In this case, the available bandwidth would mathematically be insufficient for 1080p @ 100 Hz with 10- and 12-bit color depth. You can safely forget about 12-bit mode. The monitor's panel can't display that anyway. There's no commercially available monitor that can do that. There's no relevant content, either.

10-bit also seems questionable to me, since Acer specifies the panel's color depth as 16.7 million colors. That corresponds to 8 bits per color component (bpc). Three components, so RGB, result in: 3 x 8 = 24; 2 to the power of 24 = 16.7 million.

In my opinion, this monitor can be operated at 8 bpc without missing anything.

We can look at the EDID that the monitor sends via HDMI. Please run EDID-test.exe on your PC. This will create a file named "edid-test.txt" in the same folder. Please attach this TXT file here so we can verify the EDID received from the monitor.

[ArchieD_Intel]

Hi Doddsey,

Thank you for the update. To better understand your system's configuration, we kindly request that you download the Intel® System Support Utility for Windows* software.

You can find the download link here:

• Intel® System Support Utility for Windows*
  • Here's a quick guide on using the Intel SSU:

1. Download and launch SSU.exe.
2. Check the box for "Everything."
3. Click "Scan."
4. When the scanning is complete, click "Next."
5. Click "Save."
6. Please send the saved file to us.

This information will greatly assist us in diagnosing and addressing the specific concerns with your system. If you encounter any challenges during this process or have additional questions, please don't hesitate to let us know. 

Please also attach the EDID as recommended by Doddsey. Thank you for the suggestion.

If you have any questions, please let us know. Thank you.

Best regards,

Archie D.

Intel Customer Support Technician

[ArchieD_Intel]

Hi Doddsey,

I just wanted to follow up to see if you had a chance to review the information I posted. Your feedback at your earliest convenience would be greatly appreciated. Thank you. 

Best regards,

Archie D.

Intel Customer Support Technician

[Doddsey]

Sorry I'm away from my pc. I have had a chance to look over it I will try and do it
earliest I can do it is sunday. Sorry for the inconvenience

[ArchieD_Intel]

Hi Doddsey,

I wanted to check if you had the chance to get the SSU and EDID report of your system to continue with the investigation. Your feedback at your earliest convenience would be greatly appreciated. Thank you. 

Best regards,

Archie D.

Intel Customer Support Technician

[ArchieD_Intel]

Hi Doddsey,

Since I haven't received a response from you, I will be closing this inquiry. If you need further assistance, please submit a new question, as this thread will no longer be monitored.

Best regards,

Archie D.

Intel Customer Support Technician