Can 8K60Hz 420(CVT Reduce Blank timing 1) via DP without DSC on 11th Gen Iris Xe Graphic Card?

[cruise_l]

Hi All,

I have a Dell Latitude 3322 laptop and when i connect it to a DP to HDMI protocol converter (asic CS5569) with Lecory M41h, which is a HDMI display and supports CVR7660H(8K60) YCbCr420 format, while the max resolution cannot up to 8K60 420.

- The protocol converter is configured as 4lane HBR3, which is compatible with DP1.4a, but without DSC.

- The HDMI display Lecory M41h supports 8K60 420(CVT Reduce Blank timing 1).

- If the DP link rate between laptop and protocol converter is 8.1G 4lane, the total bandwidth will be 8.1*4 =32.4Gbps, while the data volume of CVR7660H YCbCr420 is 7840*4443*60/2*24*10/8=31.34Gbps.

It is expected that the bandwith is enough for the resolution format but the actual output is only 3840x2160@60HZ. I also try this on 12th Intel Iris Xe graphic card and it seems this issue cannot be found on 12th GPU.

Please help check how could i get the CVR7660H YCbCr420 format output on 11th GPU platform.

System configuration:

Model: Dell Latitude 3322

OS: Windows 11 Professional

CPU: Intel i5-1145G7

RAM: 8GB

Storage: NVMe BC711 NVMe SK hynix 512GB 

Troubleshooting steps have been done:

- BIOS was checked and found that it is the latest version as per OEM "Dell" website

- Tried several intel ARC graphics drivers and currently the latest driver installed "32.0.101.5768" - Clean install of windows 11 with formatting of the SSD.

All the above did not solve the problem.

Dell_Latitude3322_SSU.txt attached for further analysis and troubleshooting. please help to resolve this issue

Regard

[cruise_l]

Can anyone give me some suggestions? Thanks.

[MUC]

The Dell Latitude 3320 has an USB-C port on the left side, through which a DisplayPort HBR3 signal is tunneled. According to the manual: "DisplayPort Alt Mode 1.4 over USB Type-C port"

Provided that the DisplayPort HBR3 protocol runs over 4 lanes like via the Thunderbolt ports on my NUC11TNKv7 Tiger Lake platform, then you can output an 8K signal with VESA Coordinated Video Timing - Reduced Blanking (CVT-RB).

8K @ 60 Hz YCbCr 4:2:0 8-bit (CVT-RB) = 97% HBR3

The CS5569 Protocol Converter (PCON) should forward this as

8K @ 60 Hz YCbCr 4:2:0 8-bit (CTA-861) = 100% FRL4

Please create a Report for Intel Graphics Drivers and attach the output file here so that we can see what display capabilities are reported to the graphics driver by the quantumdata M41h.

[cruise_l]

Hi MUC,

    Thank you for your valued reply.

    1. As mentioned in previous, on 12th Gen Iris Xe graphics card, it seem that 8K60 420 (CVT-RB1) can output over DP HBR3 4lanes when DSC function is disabled.

    2. While on 11th Gen Iris Xe graphics card, it seems that the max resolution only to 4096x2160@60 when DSC function is disabled. 

 

    3. As shown in your reply, the display is 8K60 420. Can you confirm that the 8K60 420 may output when the DSC function is disabled

on 11th GPU?

Attachment1 is report for intel graphics driver.

Attachment2 is the edid captured on dp aux channel

Regards

[MUC]

There are differences between what is available according to the Report for Intel Graphics Drivers and what you have captured on the DP AUX channel:

(1)   CTA-861 Extension Block:

-----------------------

YCbCr 4:2:0 Video Data Block:

    VIC 198:  7680 × 4320    50 Hz      16:9        220 kHz  2376 MHz

    VIC 199:  7680 × 4320    60 Hz      16:9       264 kHz  2376 MHz

-----------------------

When I show this to my NUC11 with i7-1185G7, the output is 8K60 as illustrated in my post above. Although it is inconsistent, it works even in the case of an additional duplicated CTA-861 block in the EDID. So yes, I can confirm that 11th Gen Iris Xe can do 8K @ 60 Hz YCbCr 4:2:0 8-bit (32 Gbps) without DSC. It would not be the first time that an Original Equipment Manufacturer (OEM) like Dell did not fully exploit the capabilities of processor-integrated graphics all the way to the physical connector. I am using the Synaptics VMM7100 (USB-C/Thunderbolt > HDMI) as a protocol converter.

So I think it is either the CS5569 or your Dell laptop and the way the DisplayPort protocol is delivered over that USB-C port. Maybe only on 2 lanes? You would have to check with Dell about that.

(2)   Block 2, DisplayID Extension Block:

-----------------------

  Version: 2.0

  Extension Count: 0

  Display Product Primary Use Case: Same primary use case as the base section

  Display Interface Features Data Block:

    Supported bpc for YCbCr 4:2:0 encoding: 8

    Supported color space and EOTF standard combination 1: sRGB, BT.601, BT.709/BT.1886, BT.2020/SMPTE ST 2084

  Video Timing Modes Type 7 - Detailed Timings Data Block:

    These timings support DSC pass-through

    DTD:  7680 × 4320   60 Hz  16:9    264 kHz   2069.76 MHz (aspect 16:9, no 3D stereo, preferred)

               Hfront 48     Hsync 32     Hback 80     Hpol P

               Vfront 16     Vsync 20      Vback 44     Vpol P

  Vendor-Specific Data Block (0x7e) (VESA), OUI 3A-02-92:

    Data Structure Type: DP

    Default Colorspace and EOTF Handling: Native as specified in the Display Parameters DB

    Number of Pixels in Hor Pix Cnt Overlapping an Adjacent Panel: 0

    Multi-SST Operation: Not Supported

    Pass through timing's target DSC bits per pixel: 9

-----------------------

The DisplayID Extension Block doesn't transport standard video timing. Here is a direct comparison:

Calculation reference:

https://tomverbeure.github.io/video_timings_calculator

https://www.cta.tech/Resources/Standards/CTA-861-OVT-Calculator

Is this an EDID of a real SAMSUNG TV?

If I show this DisplayID Extension Block additionally to the CTA-861 Extension Block to my NUC11 with i7-1185G7, then 8K can be chosen in Windows but the HDMI Resync fails. So this seems not compatible with my VMM7100. My hypothesis: The DTD in the DisplayID Extension Block is defined as "preferred", so the CTA-861 video timing in the CTA-861 Extension Block is probably overridden.