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7680x4320 detailed 8k resolution
11-12-2020, 10:28 PM
Post: #1
7680x4320 detailed 8k resolution
CRU is not allowing me to set an 8k resolution in the "Detailed Resolution" form on my W1050 computer (See attached picture); I believe the red fields in the form are disabling the "OK" button. I am using 8k hdmi to hdmi on a Samsung TV, model QN65Q850TAFXZA.

Here are the 3 Computers I am using to debug:
  • H1050 ~ home computer
  • W1050 ~ work computer
  • S1030 ~ server
Basically these are Intel custom builds with nVidia GTX graphics cards with the corresponding chipsets of GeForce GTX 1050 or 1030; H is home, W is work, and S is server. ** Suprised me that the nVidia GTX 1030 was able to do 8k **

The H1050 and S1030 computers both work at 8k on the Samsung TV; they see the 7680x4320 resolution, set the resolution, and display at both 30Hz and 25Hz; I am using an 8k hdmi cable rated for 48Gbps.

Problem is that the Samsung 8k TV is for my work computer, and does not show the 7680x4320 resolution; that is where CRU came into the picture. I have used my other computers to prove that the Samsung TV and the HDMI cable are working as expected.

Additional Info:
nVidia Control Panel also does not allow me to create a custom resolution on the work computer; the test button just says the 8k resolution is not supported.

I was able to get the timing information from both my H1050 and my S1030 computers using the nVidia Control Panel, and they match as expected. The values in CRU and nVidia Control Panel also match.

I have also replaced the GTX 1050 with a GTX 1650 and updated the drivers, with the same results.

Thanks in advance...

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11-13-2020, 12:38 AM
Post: #2
RE: 7680x4320 detailed 8k resolution
I attached the timing information as reported by the NVidia Control Panel for the Samsung 8k TV

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11-13-2020, 01:06 AM
Post: #3
RE: 7680x4320 detailed 8k resolution
You can't add resolutions greater than 4095x4095 or 655.35 MHz pixel clock with EDID detailed resolutions. You have to add it in a DisplayID extension block or as a TV resolution in a CEA-861 extension block, but that won't help because it doesn't make sense to add a resolution that the TV already defines. Where is the original extension block? You are missing the data blocks required for HDMI 2.0 to work, and the original extension block probably contains the 8K resolutions already. Also, 7680x4320 @ 25/30 Hz requires HDMI 2.1, which the GTX 1000-series doesn't support, so I don't know how it's working on the other two machines unless it's set to use YCbCr 4:2:0. HDMI 2.0 is limited to 600 MHz pixel clock, but YCbCr 4:2:0 uses half the bandwidth, effectively allowing up to 1200 MHz. For that to work, it has to be added as a 4:2:0 resolution in a TV resolutions data block with "4:2:0 resolutions" enabled, if NVIDIA supports 4:2:0 with 8K resolutions.
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11-13-2020, 01:46 AM
Post: #4
RE: 7680x4320 detailed 8k resolution
You are spot on! Color is set to use YCbCr 4:2:0 on the working computers.

Let me try to walk thru this on my own, and when I get it working I'll post the results.
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11-14-2020, 12:36 AM (Last edited: 11-14-2020, 12:59 AM by LanceMc)
Post: #5
RE: 7680x4320 detailed 8k resolution
No success yet, however here are some more details and observations...

I have attached a screen shot of the S1030 CRU SAM7040 @ 7680x4320 30Hz YCbCr420 resolution, which is under "PC" resolutions, and not "Ultra HD, HD, SD" resolutions in the NVIDIA Control Panel.

When connecting to the Samsung TV, the TV recognizes the computer as a PC. I believe it is sending the PnP monitor information at that point. Depending on the TV setting, SAM7040 is the ID when configured for 8k input; SAM703E is the ID when configured for 4k input. Samsung refers to this as "Input Signal Plus", HDMI #4 on this model is supposed to be 2.1 compliant. The first three hdmi ports are 2.0b compliant. I am only testing on HDMI #4, but it does not really matter because I think only the nVidia 30 series has HDMI 2.1 ports. I have attached 2 screen shots that confirm the "Input Signal Plus" TV setting in CRU.

Because the TV is telling the PC that it is a "PC" monitor, I believe that is why the PC resolution is available on the S1030 computer under the PC resolutions.

I am not finding the differences in CRU between the W1050 computer and the S1030 computer that will enable the "PC" 7680x4320 resolution on the W1050 computer.

Under TV Resolutions I see the checkbox for 4:2:0 resolutions, but that did not make a difference when checked. I believe that is because the computer is not seeing the TV as a TV, but as a PC monitor. I have not been able to trick the TV to tell the computer it is a TV; that may be a work around for the W1050 that I may have to come back to explore.

Next step is to compare the CRU export files... unless you have a different suggestion.

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11-14-2020, 03:31 AM
Post: #6
RE: 7680x4320 detailed 8k resolution
There's no difference between a TV and a PC monitor in the EDID. "Ultra HD, HD, SD" vs. "PC" is purely an NVIDIA-specific categorization. The SAM703E EDID doesn't include the HDMI 2.0 data block, so you can't use that for 8K. There has to be something different on the work computer. Are they running the same version of Windows? Check the scaling settings in the NVIDIA control panel under "Adjust desktop size and position" and if it gives you the choice between GPU and Display scaling, try the other option. Did you try the clean install option when installing the NVIDIA driver? You can also try DDU:
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11-17-2020, 01:25 AM
Post: #7
RE: 7680x4320 detailed 8k resolution
"Windows 10 Pro OS build 19041.630" across the lot of computers.

diff of the W1650 and W1050 export files (csv & bin) from CRU are the same.
diff of the S1050 and W1650 export files (csv & bin) from CRU are the same.
I presume this is the PnP data passed to the computer from the TV, and saved in the Registry; CRU then allows for reading / editing of this data. If that is the case, then it is a mystery to me why the NVidia Control Panel does not offer the same options using the same 1050 card and Samsung TV.

I did a clean install of the latest nVidia drivers on W1650 (same work computer using the 1650 card), this time I used the DCH (Studio Drivers) for stability with a clean install, instead of the GRD (Game Ready Drivers). No success

DDU cleaned work computer and installed latest GRD on W1650. That took a while, but no success.

To add insult to injury, and to even further taunt me, my laptop with old 419.72 drivers and a nVidia 970M chip has no problems with the option and setting of the 7680x4320 resolution on the Samsung TV.

There also seems to be higher bandwidth options with the 4k settings on all the systems that can display 8k. The W1650 is missing expected options in the "PC" section of the nVidia Control Panel. From the nVidia Control Panel:
L970M @ 3840x2160 offers only 120Hz and 100Hz Refresh rates with only 4:2:0
L970M @ 4k x 2k (native) offers 60Hz down to 23Hz, with all 4 color formats
NOTE: 4:2:0 is only an option for 60Hz with 4k x 2k.
W1650 has the same "4k x 2k (native)" options as the L970M, but the "7680 x 4320" and the "3840 x 2160" options in the PC section are missing.

Other thoughts:
  • 1650 nVidia card should support G-Sync, according to online specs
  • nVidia 3060 cards (w/ hdmi 2.1?) are suspected to be released on Dec. 2nd for ~$450
  • I bought a Radeon RX 550 card to test
  • Samsung TV has a firmware update from 1402 to 1403, installed and removed SAM7040 with CRU to get updated PnP data if any. I can't find the details about what is in the update, but this may have been an update for G Sync.
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11-17-2020, 05:53 AM
Post: #8
RE: 7680x4320 detailed 8k resolution
Radeon RX 550 card reports the "Display Specs" as 4k for the Samsung TV, see attached screen shot. There is no option to select a Pixel Format as 4:2:0; RBG, 4:4:4 and 4:2:2 are all options.

Radeon RX 550 option to create a "Custom Resolution" has the same limits as the nVidia Control Panel; it seems that I need to be able to create a custom resolution and Pixel/Color format of 4:2:0. See attached screen shot. Neither the AMD or nVidia settings allow for customizing the resolution in conjunction with setting the pixel format.

When I look in CRU, it seems that the 4:2:0 format and the 7680x4320 resolutions should be available. However the changes I make in CRU, don't seem to translate to the display control panels as options, so there is a good chance that I am not doing something correct in CRU.

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11-17-2020, 09:07 AM
Post: #9
RE: 7680x4320 detailed 8k resolution
Additional TV to help debug... LG 8k TV: 75SM9970PUA

I was able to connect up to an LG 8k with W1650 and see / set 7680x4320@30. I exported the CRU files, and from a cursory review, it looks like the Samsung TV is missing the “4:2:0 resolutions” in the CEA-861 extension block. I’ll try adding that data and compare the exported files.

This does not explain why all the other computers can do 8k, but if it gets W1650 working on the Samsung then I’ll have a solution.
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11-17-2020, 08:59 PM (Last edited: 11-17-2020, 09:44 PM by LanceMc)
Post: #10
RE: 7680x4320 detailed 8k resolution
Here is a quick recap...
  • Problem: W1650 does not have option to display 8k resolution in Windows "Display Settings" or nVidia Control Panel.
  • 3 other similar computers are able to set display at 8k with the Samsung TV.
  • CRU export of files show configurations are the same across all of the computers.
  • W1650 is able to set/display on a LG 8k TV
  • W1650 has been cleaned with DDU, and has latest nVidia GRD installed.
  • The entire ecosystem has been double checked for bad cable, etc.

What does not make sense to me is why the LG 8k (GSM0001) has CRU "4:2:0 resolutions" of 60Hz and 50Hz for 8k, but the refresh rate in nVidia Control Panel is 30Hz down to 23Hz. See attached pictures.

To test that CRU changes are being updated correctly on W1650, I removed some of the 1080p resolutions , as expected they were removed from the nVidia Control Panel.

I have added to the SAM7040, in the existing CEA-861 Extension Block, "4:2:0 resolutions" similar to what was on the LG 8k. They do not translate to 8k settings in the nVidia Control Panel.

After whittling down each resolution, and seeing unexpected behavior between CRU and nVidia Control Panel options, I am thinking that there might be an issue with:
  • Samsung PnP data stream
  • CRU handling of 8k resolutions
  • nVidia Control Panel fiddling with "Ultra HD, HD, SD" and "PC" resolution settings.

I am at a loss as to what is the problem, but there is something that is not working...[/b]

ToastyX - I can't believe this worked; something is not right...

W1650 is able to display 8k on the Samsung 8k TV (SAM7040) with an unexpected work around. I imported the LG binary file on top of the Samsung CRU settings!

Here are the steps:
1) Set CRU to "SAM7040 (active)"
2) "Import complete EDID" of the LG 8k TV (GSM0001) binary file previously exported.
3) Restart of the drivers was not required (I think... at that point when it worked I was so surprised that I rapidly started testing to confirm that it really was working!)

I was going to attach the original LG and Samsung bin files, but it seems they have the "ID serial #". Let me know what files I can post or send to you directly.

At this point I need your help determining if this is bad PnP data from the TV manufactures, or if CRU needs an update to handle unexpected formatting with the 8k data.

One last observation is that there seems to be order dependencies in the CEA-861 section. I tried to match the Samsung settings with the LG setting, but towards the end of twiddling in CRU, the results in the nVidia Control Panel were not matching the setting in CRU, until the end when I had deleted all of the CRU resolutions, and nVidia Control Panal seems to have know supported setting built into the drivers. I believe that is what you modify with your driver patch automation.

It makes me think that the best way to approach a solid work around for the community is to have 8k support added to your existing driver patch automation. I suggest that because it looks like the timing settings between the LG and the Samsung TVs are the same.

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