[Solved] NVIDIA Displayport-> HDMI adapter issues with drivers later than 457.09.

[R-T-B]

I've PM'd w1zzard and bta and they are willing to cover this, but only if we can prove my claims expand across the brand boundary. Let me explain.

I have a Club3d CAC-1085 adapter that I use to get 4K@120Hz out of my Turing card to my HDMI 2.1 TV (a 55" LG B9 OLED). It ceased to work at the high refresh, high resolution range of 4K@120Hz around the time NVIDIA added this to their fix log right after release 457.09:

Users may see a black screen when launching a game on a monitor using DSC (Display Stream Compression). [200661231]

My suspicion is that to "fix" this bug, NVIDIA disabled Display Stream Compression entirely. It seems to be supported by posts on their forums.

Display stream compression (DSC) is mainly used in 8k monitors and 4k 120hz monitors operating in HDR mode, and in 4k 120hz displayport-> HDMI 2.1 adapters. It is a required part of Displayport spec past version 1.2.

If anyone has an HDMI 2.1 TV and any nvidia card sporting a supposed Displayport 1.4 link, I would be happy to provide an adapter for free via the mail to verify my claims (you can even keep it! It's cool). Can't be LG though, as I already have that brand covered. I will even ship the adapter international, within reason, upon proof of capable hardware and willingness to test.

Really, what would be best is if we could find someone with a native displayport 1.4 monitor. You should find you are unable to select any DSC resolutions with a driver greater than 457.09. If that's true, NVIDIA is guilty of falsely advertising Displayport 1.4 compliance in their latest drivers, and on Ampere outright (the old drivers don't work on Ampere).

Please report in.

PS: Yes, I reported this to NVIDIA... over 90 days ago. I actually gave them 90 days to fix it like it was some kind of security issue. I've been met with complete radio silence. And for whatever it's worth, AMD has a similar issue, but they never had my adapter working... so... kind of knew what I was getting there. Sorry, but I feel AMD is (in)famous for weird things like that on oddball configs. Certainly worth shaming them too though, if anyone wants to test for that.

 

[newtekie1]

Wouldn't anyone with a monitor that uses DSC also be affected if what you claim is true? I'd think we'd be hearing some complains from people if their expensive monitors suddenly stopped working at the high refresh rates they paid for.

 

[R-T-B]

Wouldn't anyone with a monitor that uses DSC also be affected if what you claim is true? I'd think we'd be hearing some complains from people if their expensive monitors suddenly stopped working at the high refresh rates they paid for.

DSC generally is only used on 4K@120Hz+HDR and 8K monitors.

So yes, and there are complaints of just that on Geforce forums, and they are being completely ignored which is part of why I started investigating. ASUS/Samsung high refresh 4K monitors are also affected aparently. I guess the hardware just isn't too common (especially considering even w1zzard has none to test with).
Here are some links to DSC related complaints from geforce community, all from the same timeframe:

https://www.nvidia.com/en-us/geforce/forums/game-ready-drivers/13/428559/limited-span-classhighlightdscspan-support-since-d/

https://www.nvidia.com/en-us/geforce/forums/geforce-graphics-cards/5/419692/rtx-3060-ti-span-classhighlightdscspan-not-working/

https://www.nvidia.com/en-us/geforce/forums/game-ready-drivers/13/415422/display-stream-compression-buggybroken-in-drivers-/

https://www.nvidia.com/en-us/geforce/forums/geforce-graphics-cards/5/406137/black-screen-when-using-span-classhighlightdscspan/

https://www.nvidia.com/en-us/geforce/forums/geforce-graphics-cards/5/388621/flickeringsignal-loss-rtx2080ti-dsc12-and-club3d-c/

And likely related:

https://www.nvidia.com/en-us/geforce/forums/geforce-graphics-cards/5/428925/rtx-3080-with-samsung-odyssey-g9-blackscreen-b/

You can find more with a search. Notice a pattern?

They are likely getting away with this because DSC isn't needed on the biggest audience that has 4K@120Hz+HDR: HDMI 2.1 TVs. You can do it uncompressed there just fine.

 

[Nuckles56]

Subbing in to watch this, I have nothing I can add to this as I don't have any compatible hardware to test with but if this is the case then it is pretty piss poor on Nvidia's part that they're breaking a feature they were pushing hard this gen with the release of the 3090 (8k gaming)

 

[R-T-B]

I'll note I'm really open to the idea my adapter is just janky, but as you can see from the posts above, there does seem to be a real trend in the complaints towards it being a lack of support for DSC.

 

[phanbuey]

Interesting... i have a samsung g7 oddesey that is displayport 1.4 and i think it has to use dsc at 240hz hdr 1440p 10 bit... would this work?

 

[thesmokingman]

I'm using dsc on my G9 and rtx card without issue, nearly 8mp at 240hz.

 

[R-T-B]

Interesting... i have a samsung g7 oddesey that is displayport 1.4 and i think it has to use dsc at 240hz hdr 1440p 10 bit... would this work?

Yes. If you can test I'd love that.

I'm using dsc on my G9 and rtx card without issue, nearly 8mp at 240hz.

What card? Displayport not HDMI (pretty sure)? Driver version, most importantly? Just trying to figure out what exactly is going on here that you can / I can't etc.

 

[TheUn4seen]

There certainly is some weirdness with nVidia drivers and DisplayPort lately, but I don't think it is directly related to Display Stream Compression. I have a 3840x2160 120Hz screen which does not support DSC (Acer CG437KP), and when I used it with my old 1080ti (which also does not, AFAIK) there was horrible flickering, horizontal lines across the screen - with known good hardware. Moving back three driver versions (to 457.51, if I remember correctly) fixed it, but on any version above that the DP was horribly unstable above 90Hz. Even at 60Hz the screen sometimes didn't see the signal on any of the GPU's DP ports after a reboot or did not wake from sleep. Again, with a known good GPU, cable and screen. Moving to the 3080 fixed the issue, the signal is fully stable at 120Hz.

 

[thesmokingman]

What card? Displayport not HDMI (pretty sure)? Driver version, most importantly? Just trying to figure out what exactly is going on here that you can / I can't etc.

3090 using driver 461.40 with DP 1.4, oh and with gsync.

 

[R-T-B]

So some weirdness but not as headline grabbing as "DSC is broke."

Damn. That'll go nowhere fast, lol. Thanks all the same. The truth still matters, and it's good we did not jump to conclusions.

So it seems they only broke displayport -> HDMI 2.1 adapters as of now.

 

[purecain]

OK I think the OP is spot on in his assumptions. My pc will not give me any signal if I use my old cable which used to provide 120hz@4k with the TitanV.

So bought a new HDMI2.1 Cable(my other cable was HDMI2.0B) and when I'm starting up the pc I sometimes lose signal and then it might come back. Most of the time I have to restart due to this corruption that seems to occur after sleep mode.

Just caught it on camera for you. I'm using LG65" 120hz Both of my cards, Asus and EVGA have exhibited this behavior.

 

[R-T-B]

It may be the DSC is only disabled for hdmi?

I suppose that would make sense. They were blaming issues on Panasonic switch chips earlier, were they not? Those same ones used in various hdmi switch boxes? I bet they used DSC.

HDMI2.2

To be fair, I don't think that's a real standard so who knows what your cable is... but I still feel more is at play here than meets the eye, and I think nvidia IS playing fast and lose with the specs somewhere here.

 

[R0H1T]

So some weirdness but not as headline grabbing as "DSC is broke."

Can't you force DSC through some (driver) settings?

HDMI2.2 Cable

You sure it is HDMI 2.2 ?

 

[londiste]

OK I think the OP is spot on in his assumptions. My pc will not give me any signal if I use my old cable which used to provide 120@4k with the TitanV.
So bought a new HDMI2.2 Cable and when I'm starting up the pc I sometimes lose signal and then it might come back. Most of the time I have to restart due to this corruption that seems to occur after sleep mode.

Didn't Nvidia do fixes around video decoder and (idle) power management in the last few drivers as well?

 

[R-T-B]

Can't you force DSC through some (driver) settings?

No. It is only toggled on if it's needed for delivery.

 

[BSim500]

You sure it is HDMI 2.2 ?

^ This. There's so much junk out there with cables / conversion adaptors not meeting specs or being deliberately mislabelled from certain markets (not just video cables but everything including "Cat 7" on obvious Cat 5e, "Fast Charge" on USB cables that aren't, etc) that you really need to try at least 3-4 high-grade cables and certainly more than one DP to HDMI adaptor on a problem system to properly diagnose it.

 

[purecain]

It may be the DSC is only disabled for hdmi?

I suppose that would make sense. They were blaming issues on Panasonic switch chips earlier, were they not? Those same ones used in various hdmi switch boxes? I bet they used DSC.


To be fair, I don't think that's a real standard so who knows what your cable is... but I still feel more is at play here than meets the eye, and I think nvidia IS playing fast and lose with the specs somewhere here.

Its early here buddy I had just woken up... Its a 2.1 cable, the older cable which provided 120hz/4k was 2.0B. The latter cable gives no signal at all.

 

[R-T-B]

more than one DP to HDMI adaptor

There is literally only one Displayport->HDMI 2.1 adapter on the market that does hdmi 2.1, so no can do. I own a few of them. The adapter is not the culprit here.

 

[qubit]

I think you're on to something here. Unfortunately, I only have a 4K60 TV, so can't test it for you, although I do have an MSI 2080 SUPER.

I think this will eventually be fixed rather than bodged like this, but these displays will have to become more popular first.

 

[R-T-B]

I feel it's not going to be fixed until 8K comes around, because with hdmi 2.1 you don't need dsc for 4K high refresh Only these weird adapters need it. And aparently displayport dsc is working.

 

[londiste]

I wonder if there is a difference between RTX2000 and RTX3000 series cards when it comes to this.

 

[R-T-B]

I wonder if there is a difference between RTX2000 and RTX3000 series cards when it comes to this.

From what I have linked above in forum reports from the geforce board, it would not appear so. But RTX 3000 has hdmi 2.1, so why bother with an adapter requiring dsc really?

 

[Gmr_Chick]

I'm not sure I'd be able to help, but I just wanted to say that I'm running a GTX 1660 Super with a Club3D display port cable (would have to check the packaging to see what version it is) attached to an Aorus CV27F 165Hz monitor. Ya know, just in case it helps you

 

[R-T-B]

I'm not sure I'd be able to help, but I just wanted to say that I'm running a GTX 1660 Super with a Club3D display port cable (would have to check the packaging to see what version it is) attached to an Aorus CV27F 165Hz monitor. Ya know, just in case it helps you

Afraid I've narrowed it down to the HDMI side of my adapter now, but I appreciate the offer.