Intel Iris Xe 4k output question - can this chipset output 4k@60Hz 8-bit color ycbcr444 without HDR?

[bryanlakatos]

I posted this as a reply to an older related thread, but I figure that might not get any attention, so here it is again:

I have a Lenovo ThinkBook with Intel Iris Xe graphics and an i7-1255U. I'd like to run 8-bit 4k@60Hz YcbCr444 (4:4:4 chroma subsampling) but do not require HDR. Assuming I'm using a compatible display, what are the possible ways to get there? Does Iris Xe support this over HDMI?

Is HMDI 2.0/2.0b/2.1 an option with this chipset? Unfortunately, Lenovo doesn't mention which version of HDMI is offered in the laptop spec sheet I can find, so I'm thinking maybe it's more a function of the Iris Xe chipset?

How about via Thunderbolt 4, which this laptop also has? Thunderbolt 4 has plenty of bandwidth - has anyone had success with getting ycbcr444 via a Thunderbolt connection?

Before I go hunting for a TV to purchase, I'd like to see if it's even a possibility to run 4k@60Hz 4:4:4 with this laptop. 

Thanks!

[Alberto_R_Intel]

bryanlakatos, Thank you for posting in the Intel® Communities Support.

In reference to this scenario, first, it is important to mention that when using a mobile device, such as a laptop, everything on that system is customized by the computer's manufacturer. They can enable/disable BIOS settings as well as features and functions of the device to comply with the functionality advertised for their products.

With that in mind, in order to try to provide the most accurate response to your inquiries, I will do further research on this matter. 

In the meantime, in the following links, you will find other details about how to set the chroma subsampling and additional requirements that should be useful for you:

https://www.intel.com/content/www/us/en/support/articles/000087657/graphics.html

https://www.intel.com/content/www/us/en/support/articles/000057279/graphics.html

As soon as I get any updates, I will post all the details on this thread.

Any questions, please let me know.

Regards,

Albert R.

Intel Customer Support Technician

[bryanlakatos]

Thanks!

[DeividA_Intel]

Hello bryanlakatos, 

We are still investigating this issue and to continue I will need the report from the Intel® System Support Utility (Intel® SSU).

• Download the Intel® SSU and save the application on your computer: https://www.intel.com/content/www/us/en/download/18377/intel-system-support-utility-for-windows.html  
• Open the application, check the "Everything" checkbox, and click "Scan" to see the system and device information. The Intel® SSU defaults to the "Summary View" on the output screen following the scan. Click the menu where it says "Summary" to change to "Detailed View".  
• To save your scan, click Next and click Save.  

Regards,  

Deivid A.  

Intel Customer Support Technician  

[bryanlakatos]

OK, so I learned a couple things. I have been able to test this laptop with Iris Xe graphics on a 4k TV that a desktop computer is successfully connecting to at 4k@60Hz and 4:4:4 (though RGB doesn't work, it's not really needed as 4:4:4 chroma subsampling is enough). Using the same HDMI cable and TV input that this computer is using, this laptop cannot match the desktop computer's settings using the HDMI connection on the laptop. Namely, it can do 4k 4:4:4, but only at 30Hz, or I can do 4k at 60Hz with only 4:2:0 compression. It can't do 4k at 60Hz and 4:4:4 (or RGB).

Using a Thunderbolt/USB-C to HDMI dongle adapter, this laptop is able to connect to the TV as I need it to without issue. Same TV input and cable, through the dongle, and this same laptop hits 4k@60Hz at 4:4:4 color easily. Perhaps this is expected, or this is a bug. Either way, I was able to get my requirements out of this laptop via the Thunderbolt connection. 

I'm happy to submit the SSU report. Do you want me to just attach it to this thread? Will the report contain any sensitive or potentially private information?

Thanks,

[n_scott_pearson]

If it works as it should using the USB-C port but doesn't using the laptop's HDMI port, this is an indictment of the quality of the HDMI port implementation on this laptop (not the first time I have heard complaints regarding Lenovo's HDMI port implementation).

Sadly, the SSU report *does* contain what I consider sensitive, personally identifiable information (serial numbers, amongst other things). I have asked Intel on a number of occasions to fix this, but they have outright refused. If you are nervous about this kind of information being included in a public posting, you can attach the report to a private message (PM) to Deivid (click on your avatar picture and select Messages to access this capability). Sadly, this means that the volunteers here (like me) will not be able to help with this analysis.

...S

[DeividA_Intel]

Hello bryanlakatos, 

Thanks for the information provided, based on this, seem that the HDMI cable that you have does not have enough bandwidth to reach 4k@60Hz at 4:4:4. I recommend you test with a certified HDMI cable version 2.1 to discard any issues with the cable or the port.

I will send you an email to the e-mail address associated with your community profile. Reply to this email with the Intel® SSU report and also with a graphics report using the HDMI cable and another one with the Thunderbolt dongle.

If possible let me know in the email if you are able to test an HDMI 2.1 version.

Thanks for your comprehension.

Regards,  

Deivid A.  

Intel Customer Support Technician  

[bryanlakatos]

I will look for the email. Please note, though, that it's not the cable that's the issue. In the results I shared above, I clearly stated that I tested the laptop using the same cable that my desktop PC uses to achieve 4k@60Hz 4:4:4. The same cable also carries the target quality signal from the Thunderbolt adapter. I question your assessment.

[DeividA_Intel]

Hello bryanlakatos, 

I am sorry for the inconvenience. I will be waiting for your response to the email sent to the e-mail address associated with your community profile.

Thanks for your help and comprehension.

Best regards, 

Deivid A.  

Intel Customer Support Technician 

[DeividA_Intel]

Hello bryanlakatos,  

After checking your thread, I would like to know if you need further assistance. 

If so, please let me know. 

Regards,  

Deivid A.  

Intel Customer Support Technician  

[DeividA_Intel]

Hello bryanlakatos,  

I was checking your thread and see that we have not heard back from you.  I’m going to close your post, but if you need further assistance, please do not hesitate to create a new thread. 

I recommend you check this issue with the laptop manufacturer since they can place restrictions and limitations on their products.

Regards,  

Deivid A.  

Intel Customer Support Technician