Samsung G95NC and weird EDID?

[laxu]

So I've been trying to look into the Samsung G95NC 7680x2160 superultrawide to see if I could add 120 Hz support when the display OSD is set to 240 Hz.

What happens on Nvidia 40 series is that setting the OSD to 240 Hz drops refresh rate to 60 Hz and 120 Hz is just not available unless you set OSD to 120 Hz.

I exported the EDID in both 240 Hz and 120 Hz mode using CRU to see if there are differences I could use to make the 240 Hz EDID do my bidding.

But what I discovered, is that there are absolutely no indications of the 7680x2160 resolution in any of the descriptors. I tried checking it with both CRU, AW EDID Editor, and EEditGold. Same deal on all of them.

How is this possible? Does Samsung have some hidden EDID that these apps cannot read or parse?

[ToastyX]

If there is an "extension override" data block in the CTA-861 extension block, then there are additional extension blocks that CRU doesn't read yet. Also NVIDIA's driver ignores EDID overrides if the pixel rate exceeds a certain limit, so it won't have any effect anyway.

[laxu]

(10-14-2024 10:51 PM)ToastyX Wrote:  If there is an "extension override" data block in the CTA-861 extension block, then there are additional extension blocks that CRU doesn't read yet. Also NVIDIA's driver ignores EDID overrides if the pixel rate exceeds a certain limit, so it won't have any effect anyway.

Is there any other application that is capable of reading or editing those data blocks?

I have noticed that interestingly the display will show both 240 and 120 Hz options for less than native resolution if VRR is disabled while the OSD is at 240 Hz. I assume this is some Samsung weirdness where it just loads a different EDID and the VRR enabled one is somehow more barebones, but dumping the EDID in different modes I can't see any noticeable difference between them.

[ToastyX]

Run this and post the edid-test.txt file here: https://www.monitortests.com/edid-test.zip

[ToastyX]

You have overrides in place so it's reporting those. I need to see them without the overrides. Run reset-all.exe and restart first.

[laxu]

(10-16-2024 11:56 PM)ToastyX Wrote:  You have overrides in place so it's reporting those. I need to see them without the overrides. Run reset-all.exe and restart first.

My bad. Ran reset-all, restart and attached to this post are the results from edid-test.

[ToastyX]

Here are the EDIDs with the extension count adjusted so CRU can read them:

  G95NC_120Hz_VRR.bin (Size: 384 bytes / Downloads: 11)
  G95NC_120Hz_no_VRR.bin (Size: 512 bytes / Downloads: 17)
  G95NC_240Hz_VRR.bin (Size: 512 bytes / Downloads: 26)
  G95NC_240Hz_no_VRR.bin (Size: 512 bytes / Downloads: 20)

I will update CRU soon to read the additional extension blocks without modification, but currently NVIDIA's driver ignores EDID overrides for monitors with these high pixel rates, so my priority is working on CRU 2.0 at the moment.

[laxu]

(10-18-2024 09:07 PM)ToastyX Wrote:  Here are the EDIDs with the extension count adjusted so CRU can read them:


I will update CRU soon to read the additional extension blocks without modification, but currently NVIDIA's driver ignores EDID overrides for monitors with these high pixel rates, so my priority is working on CRU 2.0 at the moment.

Thank you for your hard work!

Checking through the EDIDs it is clear that the G95NC loads a different EDID for VRR vs no VRR mode. For reasons unknown, the 240 Hz VRR EDID just does not list 120 Hz options at all, while the no VRR version does.
So unsurprisingly Nvidia cards think "Oh, I can't do 7680x2160 @ 240 Hz so let's drop down to 60 Hz because that's the only option this display provides."

I guess not being able to load these EDID overrides due to that Nvidia pixel rate issue means that you can't just add 120 Hz options to the 240 Hz VRR EDID and load it instead?

[ToastyX]

(10-18-2024 09:57 PM)laxu Wrote:  I guess not being able to load these EDID overrides due to that Nvidia pixel rate issue means that you can't just add 120 Hz options to the 240 Hz VRR EDID and load it instead?

Right now there doesn't seem to be a way to add custom refresh rates with the pixel rate issue. Even their own control panel custom resolutions are disabled. It would be possible if they allowed EDID overrides.

[Zyarra]

(10-18-2024 09:07 PM)ToastyX Wrote:  Here are the EDIDs with the extension count adjusted so CRU can read them:


I will update CRU soon to read the additional extension blocks without modification, but currently NVIDIA's driver ignores EDID overrides for monitors with these high pixel rates, so my priority is working on CRU 2.0 at the moment.

Sir. We all really, REALLY appreciate your work.
Amazing.

Will 2.0 override the nvidia behavior? Or that's not possible and we must wait for Nvidia to do sth(not likely to happen)

Ps how come windows hdr calibration is able to override the peak brightness even with dsc active?
I tried to find out how it's doing it but it's beyond me...