4k120hz hdr 12bit gets washed out after a reboot, until i switch to 60hz then back to 120hz

I bought the new club3d cac-1085 4k120hz dp1.4 adapter to hdmi2.1

I have a 2080ti and a lg C9.

Running nicely at 4k120hz 12bit rgb with hdr, until i reboot then the colours get washed out.

Switching to 60hz then back to 120hz will fix the issue.

Could it be an issue with nvidia drivers? or the adapter or a combination?

Any nvidia experts here know what is happening?

 

It must be an OS level bug. Windows 10 is not stable for hdr content. Never was. Hit or miss.

 

did you upgrade your hdmi cable to a 2.1 one as well? if you didn't thats more then likely the cause, your just bottle necking the cable at this point if you didn't, i didn't know display port even supported hdmi 2.1 i have the lg c9 as well i may have to look into this adapter and a new hdmi cable as well

 

Yes i already have a belkin uhdmi 48gbit/s 1m cable.

I ordered a new club3d cable, see how that goes, but i doubt it as other people are reporting the same problem, i mean it could most likely be the adapter, but i guess we will never know the workings between the gpu/os/adapter/tv.

 

For what its worth, I tested a cheap Dynex (Best Buy brand for those in the USA) 6 foot/1.8 meter HDMI High-Speed cable (High-Speed means rated for only 10.2gbps) with the recently-new Denon AVR-S960H i purchased.

In its HDMI diagnostics menu, this 10.2gbps cable reportedly passed the full 40gbps the receiver supports
(if you plug a cable into the 8k HDMI input and output 1 and run the HDMI cable test feature).

So before you all go out and buy new cables, try and see if your existing cables will work with your HDMI 2.1 setups.

 

Yea not sure i'm going to believe that without proof and you really can't prove thats the cable you have plugged in so good luck convincing anyone of this without going and buying a new cable and making a video of unpacking it and plugging it in and running the test, sorry but cables can only do as much as they are allowed and the high speed cables can only go upto the low 20's thats with the spendy monster cables at that...

i'm going to pass this one up to windows because as we all know it's jammed packed full of bugs lol
but i do have a question i'm not a shooting game person i'm a racer nfs an forza all on my pc, but anyway FPS don't matter that much to me I go for picture/video quality, so i'm assuming that your running stock rgb output color format? I use YCbCr444 at 4k@30hz and was wondering with that adapter if i could do @120hz with the 444? if you wouldn't mind testing that? its under the change resolution tab in nvidia control panel at the bottom, if not thats cool but before i spend money on a cable i'd like to know if it works with the way i like to set things upsince my pc isn't just a gaming pc but also my movie/atmos watcher so video an sound quility are a must for me

 

I can only get 4k120 RGB with HDR at the moment(that's pretty much the best/max anyway) the adapter works ok, apart from losing signal when resolution changes, but easy fix is to press win+ctrl+shift+B

 

Does it work using 10bit? Why are you using 12 bit?

 

Alright, time to make that video this week.

Edit:

So here is the video, it was not the Dynex cable that could supposedly pass 40gbps, but a High-Speed HDMI cable that i got with a rented set-top box



Also retested the same cables a few days later as some of the new Denon AVR's have reported inconsistent test results.

 

Does G-Sync Compatible work with this adapter?

Yeah, 4k120 12bit RGB is probably out of the DP 1.4 bandwidth (not for HDMI 2.1 though).

 

Yeah i stopped using 12bit, just using 4k120 10bit rgb with hdr since the panel is max 10bit.

There was no real reason i was using it, i think nvidia defaults to it.

 

No gsync doesn't work,maybe in a future adapter.

It's not, i already can get that resolution. the DP1.4 uses DSC can output very high up to 8k @75hz - 78.13 Gbit/s on the uncompressed end

 

i have the same setup, 2080ti and a lg C9, tried the cac-1085:

1. does not do gsync (this kind of sucks even if you do 100hz instead of 120hz, hard to maintain that framerate in many new games)
2. yes, mine also gets all weird after reboot (also even just switching HDR on/off in windows can cause it to have issues) Sometimes to get the resolution to reset, i have to reboot the adapter (simple pull power and replace)
3. the cac-1085 gets super hot just normally hooked up, dont even need to be in a game.
4. 4k120hz 12-bit desktop is glorious (when it works). Also 4k HDR movies encoded at ~24hz look beautiful in 120hz (no 3:2 pulldown). Every tv I ever had that supported 24hz film mode, was weird when switching the tv to 24hz in windows to match film. But 120hz is buttery smooth.
5. with this adapter, it wasnt getting the proper handshake for audio (with eARC passthrough of the C9), and it defaulted to 2ch PCM. I was able to override this to 7.1ch with CRU (Custom Resolution Utility), but sometimes on waking up the PC either loses the audio device totally, or reverts to 2ch... If you connect a separate cable directly to the receiver, this will not affect you.
6. the LG C9 forces overscan when enabling 4k 100hz or 120hz, which cannot be disabled with the normal "Just Scan" in aspect ratio options. Someone on reddit figured out that you need to disable "Screen Shift" which is normally on to help with burn-in in the OLED. Can confirm this worked for me.

I switched back to normal hdmi while im playing death stranding, because it just runs smoother with gsync @60hz than a choppy 100/120hz with or without vsync (aka no gsync)

I think ultimately the 3080ti (or 3090 or w/e it will be) will be the solution we are waiting for, with straight hdmi 2.1 (and hopefully LG updates the C9 to do gsync 4k@120hz)

 

Here is a screenshot of 4k @120hz enabled, only RGB or ycbcr422 (no 444 which is odd...)

Spoiler

https://imgur.com/a/mwSXpIE

Using this cable: https://smile.amazon.com/gp/product/B07ZDDV6DT/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

Edit: I also have a monoprice 6ft cable, may end up testing but right now im using the Audiano because its rated for 8k and 10ft long (might be why it randomly artifacts every once in a while, after switching res)

 

Lol the ad for the cable says fibre optic hdmi2.1 cable, what a crock..

 

What's crocky about it?

 

screenshot of 4k @120hz enabled only way I can have 120Hz for 4k ycbcr420

Spoiler

http://www.imagebam.com/image/30cb031354164432

2080ti and Samsung Q90R, hdmi 2.1 cable

 

4k@120@12bit does not really exist. Get something real to play with people. Find something important. That ain't cut it. Move on.

 

Me and my C9 completely disagree.

I think that what is not ready is Windows and the Nvidia driver. This will obviously change with the first Ampere driver.

 

I didn't know for sure, I did that only on papers. I have a B9 and I set those values, but I never played any game or movie, I suppose if it works on desktop properly with HDR, it works globally then. I am glad I have AMD gpu.