New TV won't accept any changes from CRU when Game Mode is on

[le07]

(12-16-2022 02:33 AM)ToastyX Wrote:  

(12-15-2022 03:50 PM)le07 Wrote:  Hello, I've used CRU for a long time with different displays without issues, but 2 months ago I bought a new TV (Samsung 50QN90B) and it doesn't seem to accept any changes from CRU depending the device I connect

TV native resolution is 3840x2160, and can go up to 144Hz, although this refresh rate doesn't show up in CRU.

When I connect my TV to my old Laptop with an GTX 1060, I can make changes with CRU just fine with game mode on or off, but when I connect it with my PC with an RTX 3080 and turn game mode on, CRU profile doesn't include the extension block with HDMI resolutions, and if I try to create custom resolutions, or manually add a extension block to change VRR range, nothing works, the TV simply ignores everything, the only change it seems to accept is when I change the name of the TV.

This is something NVIDIA's driver is doing. The driver is reporting no extension blocks even though there should be one. I've heard of this happening with displays that use DisplayID instead of EDID, but that normally applies to DisplayPort monitors. I haven't heard of any TVs using DisplayID with HDMI so far. If that's the case, there is currently no solution.

The presence of an extension override data block suggests there might be another extension block that CRU can't read, but that shouldn't prevent the first extension block from being readable. You can use EDID/DisplayID Writer to read the first extension block directly from the monitor. Check if it can read a DisplayID as well.

(12-15-2022 03:50 PM)le07 Wrote:  I am also unable to create custom resolutions or use DSR using NVIDIA control panel.

Usually when this happens it's because NVIDIA's driver doesn't currently support custom resolutions or DSR with display stream compression (DSC), but 3840x2160 @ 144 Hz shouldn't require DSC unless the color depth is higher than 8 bpc.

I tried to export the profile CRU with the extension block on my GTX 1060, and imported it to my PC with the RTX 3080, but it still didn't work.

DSC was one of my first suspicions

I was reading this in NVIDIA support page:
https://nvidia.custhelp.com/app/answers/...a_id/5338/

And it says:
"Using a monitor/display with DSC support over HDMI 2.1:
Display Stream Compression over HDMI 2.1 is supported on Ampere class (GeForce RTX 30-series) GPUs. "

Also, text at 4k144 in this TV is less sharp compared to 120Hz and below, I am being able to use it with a HDMI 2.0 cable and Control Panel and Windows settings says it's running at Full RGB 8bit, but I believe it's not showing the correct information, because my cable wouldn't have the bandwidth to support that, but RTings and other people with a HDMI 2.1 cable also warn about 144Hz not having proper Chroma 4:4:4

https://www.rtings.com/monitor/reviews/s...qn90b-qled

"in Game Mode with the input label set to 'PC'. The text clarity is much worse with a 144Hz signal... This is because it doesn't display proper chroma 4:4:4 with a 144Hz signal"

But after searching for some answers at Reddit, I discovered a way to insert custom resolutions using Windows registry.

If you go to "HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\Class\{4d36e968-e325-11ce-bfc1-08002be10318}\0000", you can edit "NV_Modes" and insert a custom resolution followed by =1.

   

After a restart, the custom resolutions will appear at NVIDIA Control Panel, and work just fine:

   
   

So there is no reason for the option to create custom resolutions to be locked in control panel, I will try to contact NVIDIA driver support and see what they think about it.