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LG 48CX

Interesting to know if LG will solve this internal downsampling issue on the 48CX. It breaks the whole point of owning one.
Or maybe they will add the full 4K support only in 48CXI models next year that will probably come with increased price and a new chip... Since their current chip in the 48CX simply doesn't support such resolution. In that case I wonder how it passed the Nvidia certification.
 
Murzilka said:
Interesting to know if LG will solve this internal downsampling issue on the 48CX. It breaks the whole point of owning one.
Or maybe they will add the full 4K support only in 48CXI models next year that will probably come with increased price and a new chip... Since their current chip in the 48CX simply doesn't support such resolution. In that case I wonder how it passed the Nvidia certification.
Click to expand...

To be fair the difference is hard to see in regular use. People who just watch TV/movies or play on consoles will be none the wiser.
 
On my pc, when my 43" samsung nu6900 defaulted to it's named input being named HDMI instead of PC, it dropped the (RGB) 444 and I could tell instantly on torn edges of text. I would never find that acceptable on any screen. Once I changed the input back to "PC" the screen supported full rgb properly and the tattered text went away.

While this is the most obvious in static text on the desktop it happens in PC games and photos too. Some pc games also have a lot of text, including RPGs and RTS, storied games and plenty of games with stats. It doesn't just affect text either, it's just more obvious and painful to look at in text. Movies are made in 4:2:0 so yeah, not going to be an issue there. Existing consoles too but I don't know what the new consoles will be considering they will have hdmi 2.1.

The quest(1) OLED VR headset supports these incidentally ... Rec2020, Rec 709, DCI-P3, Adobe RGB
https://developer.oculus.com/learn/color-brightness-mastering/?locale=en_US
Color Management
The Oculus Go and Rift S’ LCD limitations prevent them from meaningfully differentiating brightness levels below 13 out of 255 for 8-bit sRGB or 0.0015 out of 1.0 max for linear-RGB shader output values. If a VR app uses an extensive amount of these dark ranges, it is recommended to author content in a higher brightness range as much as possible.

We recommend app developers to master all of their applications for the Oculus Rift and Rift S to the Rift CV1 color space on an Oculus Rift CV1, Rec.2020 color space for Oculus Quest, and Rec.709 color space for Oculus Go. The OLED display has a wider color gamut than the LCD and allows for richer visual experiences. VR apps authored for the Oculus Go and Rift S color spaces tend to have dull or washed out colors when viewed on the Oculus Quest and Rift CV1 displays.

Requested rectilinear-mirror outputs are composited without any color space adjustment. However, if a client requests a post-distortion (i.e. non-rectilinear) mirror output, it will be provided with the same color adjustment that was applied for the HMD output. Post-distortion mirror may not have acceptable color-space accuracy when viewing on desktop.
Click to expand...
 
Oh boy with all these issues that keep on popping up, I am so glad I did not end up selling my Acer X27 yet 😵 my CX still makes for a great TV at least....except for the raised blacks in Dolby Vision 😑
 
They are wrinkles that could very well get ironed out.. This is very early adoption at this point. A hdmi 2.1 gpu wasn't available until a day ago more or less if that.

If it turns out to be something unfixable at the hardware level I might start looking at a 55" C9 or E9 in november I guess, if available. I'm not really interested in BFI so other than the size I don't think it would be missing out on anything really.
 
Murzilka said:
Interesting to know if LG will solve this internal downsampling issue on the 48CX. It breaks the whole point of owning one.
Or maybe they will add the full 4K support only in 48CXI models next year that will probably come with increased price and a new chip... Since their current chip in the 48CX simply doesn't support such resolution. In that case I wonder how it passed the Nvidia certification.
Click to expand...

For what it's worth, I'm pretty sure 4:4:4 has been being downsampled to 4:2:2 since the B6, since I'm pretty sure my B6 is doing that. RGB Full is fine for text rendering if you keep sharpness down a bit though (I think I'm at 10 sharpness). I've actually had *more* problems trying to get 4:4:4 to work and have stuck with RGB since then.
 
elvn said:
They are wrinkles that could very well get ironed out.. This is very early adoption at this point. A hdmi 2.1 gpu wasn't available until a day ago more or less if that.

If it turns out to be something unfixable at the hardware level I might start looking at a 55" C9 or E9 in november I guess, if available. I'm not really interested in BFI so other than the size I don't think it would be missing out on anything really.
Click to expand...

Whats interested is people claim that VRR works with the adapter, so I'm actually more inclined to blame NVIDIA right now for any VRR issues. The fact the adapter works means the TV is known able to accept the signal.
 
SixFootDuo said:
Well, some strange happenings with me.

I own a C9 along with a new RTX 3080. After a long painful wait, I can finally game @ 4K 120hz which is ... amazing, Game changer.

Intitially, I had a LOT of really weird trouble with my old cable which was a premium 4K 60hz rated gold plated 18awg 6' cable. Weirdness in that parts of the screen would be missing, for example, about 30% of the right side would just be gone as in a black section. Sometimes the left side and sometimes a narrow band of blackness in the middle. I quickly deduced that this must be my current cable and the bandwidth limitations of that cable.

So a quick trip to Microcenter and $27 later I had a 8k @ 60hz / 4K @ 120hz 48GBs 6' HDMI cable. Did it fix the problem, yes, ( I think ) but I had to reboot, remove the plug and play monitor from the hardware tree, reboot again, reinstall drivers and it started working .... KIND OF.

COD Warzone would not launch and instead go straight into a unrecoverable black screen. After fiddling around, turning off Gsync ... yes, TURNING OFF Gsync ... it fixed my problems.

On a side note, COD Warzone with high / ultra settings runs at 110FPS @ 4K @ 120hz Full Screen Border-less. It's beautiful.

Can anyone help me with the Gsync issue?? I would like to turn it on and use that feature and have COD Warzone play correctly. In fact, and advice on how I should have my settings???

View attachment 280292View attachment 280293View attachment 280294View attachment 280295
Click to expand...
Thanks for posting this, and congratulations on your new card purchase! I suspect a lot of 30xx owners are in for a surprise when they realise their own HDMI cables aren't really ready for this beast of a TV/display.... me included. But I didn't spend a lot on them, it'll just be a case of waiting til I can get a card and also reading reviews on here for those cables that are known to work.
 
Alright so can I get the TDLR on the C9. HDMI 2.1 is fully working with a 3080 at 4:4:4 but as of now VRR/gsync is broken on both the C9 and CX? It probably is never going to get fixed on the C9 I bet.
 
gamerk2 said:
Whats interested is people claim that VRR works with the adapter, so I'm actually more inclined to blame NVIDIA right now for any VRR issues. The fact the adapter works means the TV is known able to accept the signal.
Click to expand...
VRR isn’t even an option with the adapter.
 
gamerk2 said:
For what it's worth, I'm pretty sure 4:4:4 has been being downsampled to 4:2:2 since the B6, since I'm pretty sure my B6 is doing that. RGB Full is fine for text rendering if you keep sharpness down a bit though (I think I'm at 10 sharpness). I've actually had *more* problems trying to get 4:4:4 to work and have stuck with RGB since then.
Click to expand...

RGB is 444. YCbCr 444 just has to be converted to RGB.

https://www.reddit.com/r/hardware/comments/8rlf2z/psa_4k_144_hz_monitors_use_chroma_subsampling_for/
Since RGB-format images don't have luma or chroma components, you can't have "chroma subsampling" on an RGB image, since there are no chroma values for you to subsample in the first place. Terms like "RGB 4:4:4" are redundant/nonsensical. RGB format is always full resolution in all channels, which is equivalent or better than YCbCr 4:4:4. You can just call it RGB, RGB is always "4:4:4".
Click to expand...

Also, chroma subsampling is not a form of compression, because it doesn't involve any de-compression on the receiving side to recover any of the data. It is simply gone. 4:2:2 removes half the color information from the image, and 4:2:0 removes 3/4 of it, and you don't get any of it back. The information is simply removed, and that's all there is to it. So please don't refer to it as "4:2:2 compression" or "compressed using chroma subsampling" or things like that, it's no more a form of compression than simply reducing resolution from 4K to 1080p is; that isn't compression, that's just reducing the resolution. By the same token, 4:2:2 isn't compression, it's just subsampling (reducing the resolution on 2/3 of the components).
Click to expand...
 
Morkai said:
The poster of the screenshot is someone I trust would notice 4:2:2 and be claims 4:4:4 works. Also one of the first I see with a 3080, most previous info was with the sketchy dp-adaptor.
Click to expand...
The internal downsampling is not noticeable in the NVIDIA Control Panel's white / blue / black colour scheme. It's clearly visible in "chroma-444.png". A native 4:2:2 signal looks much worse and is instantly noticeable, which is what people would be looking for. Perceptually, the internal downsampling is in-between 4:2:2 and 4:4:4.

If it was an adapter issue, it doesn't explain why 1440p 120 Hz works fine. If anything, odd resolutions like 1440p should be broken while 4K and 1080p should work fine, but it's the opposite. We already know 1440p 120 Hz is a "special" resolution on the C9 and CX.

gamerk2 said:
For what it's worth, I'm pretty sure 4:4:4 has been being downsampled to 4:2:2 since the B6, since I'm pretty sure my B6 is doing that. RGB Full is fine for text rendering if you keep sharpness down a bit though (I think I'm at 10 sharpness). I've actually had *more* problems trying to get 4:4:4 to work and have stuck with RGB since then.
Click to expand...
RGB is converted to 4:4:4 or 4:2:2 in the TV. The older models supported 4:4:4 rendering with PC icon. With the CX, 4:4:4 is downsampled even with PC icon when the resolution is 4K or 1080p 120 Hz. 60 Hz works fine. The C9 does not have this issue at 120 Hz.
 
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st1650 said:
Hopefully a firmware upgrade from LG is in the works.
Click to expand...

How do we even know the issue is known by LG? Does someone need to open a ticket with them or something? Would that even get proper escalation? It feels like Nvidia has a partnership / interest in the LG OLED as its the only TV certified for GSync as I understand it. They should push this up the chain.
 
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lors said:
It's Nvidias fault:

https://www.nvidia.com/en-us/geforc...e-45638-game-ready-driver-feedback-thread-re/

Massive issues also on other monitors with Gsync-compatible. Perfect timing xD
Click to expand...
How? There is absolutely no mention of the downsampling.

Based on the appearance of the image, the GPU is indeed sending a true RGB signal. 4K 120 Hz RGB internally downsampled with PC icon looks identical to 4K 60 Hz RGB internally downsampled without PC icon. With PC icon, 4K 60 Hz RGB is not downsampled.
 
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Monstieur said:
How? There is absolutely no mention of the downsampling.

Based on the appearance of the image, the GPU is indeed sending a true RGB signal. 4K 120 Hz RGB internally downsampled with PC icon looks identical to 4K 60 Hz RGB internally downsampled without PC icon. With PC icon, 4K 60 Hz RGB is not downsampled.
Click to expand...

Sorry, i was referring to the gsync black screen issue.
 
So the downsampling is still occuring if you have a 3080 at 120Hz/4K? If so that is very disappointing, one of the main reasons why I bought this LG OLED is to get 120Hz 4K at 4:4:4 with a 3000 series card.
 
Thank you early adopters, I can now search for a deal on a C9 instead. 55" kinda sucks, but I can move my desk back a bit from my wall mount....again.
 
So as of now it seems like:

- nvidia VRR at 4k 120hz 444 on hdmi 2.1 is broken ... most likely nvidia driver issue and affects the C9, E9, CX as well as other "g-sync compatible" monitors. This should be fixed in a reasonable amount of time I'm guessing

- LG CX internally downsamples 4k 120 Hz RGB to at least 4:2:2, losing color information and making text "tattered". This does not happen on the C9 and E9 from what I've heard. So far no word on if it's fixable via firmware on the CX at some point of if it's a hardware limitation.

The fact that the ports are 40Gbps is making some people nervous about the CX having cut some corners hardware wise. Hopefully that isn't the case. It could just be early adoption wrinkles software wise. Hopefully it will all get sorted out by november which I've been waiting a long time for as my time to purchase an OLED.
 
Just got my triple CX48's installed for my sim rig. Bit of an issue with the center screen which is the one I was using first before I bought the other two CX's.

The two new ones (left and right) both went through the TV setup and automatically turned on HDR and were in HDR mode. They are on nice cables running to the Club 3d Display Port Adapters.

The center TV is running on HDMI. I swapped out the HDMI cable and still can't get HDR on this center CX48. I am running them on on 2 Pascal Titans in SLI...

I can't seem to find a setting in the CX48 menus to turn on HDR. Am I missing it somehow?

Or should I get another CLUB 3d Adapter and go all display port?

EDIT: So I just tried switching the center to one of the display ports (same HDMI cable), and it automatically went into HDR. So it's an HDMI issue. Sigh. Is it the old HDMI ports on the Pascal Titans? I don't even know what version they are.
 
Take a look of this video showcasing the 3080 along with a 48 CX (link takes you to 4:23 timestamp). Sorry for the noob question but what's the difference between setting the output color format to RGB vs 4:4:4 vs 4:2:2 in the NVIDA interface? Does RGB = 4:2:2? If so why present both options?

 
RGB is RGB and is the highest quality. It's a very noticeable difference for PC use with text.

But the problem is what the TV does when receiving that signal. Right now at anything higher than 60hz (with 4k) it's converting it to something like 422 (or somewhere between 422 and 444).
 
kalston said:
RGB is RGB and is the highest quality. It's a very noticeable difference for PC use with text.

But the problem is what the TV does when receiving that signal. Right now at anything higher than 60hz (with 4k) it's converting it to something like 422 (or somewhere between 422 and 444).
Click to expand...

Understood. For testing purposes how to you tell that the TV is converting / down sampling to the lower format? Just eyeball or is there a diagnostic mode on the TV to see what format its actually outputting?
 
As
domenic said:
Understood. For testing purposes how to you tell that the TV is converting / down sampling to the lower format? Just eyeball or is there a diagnostic mode on the TV to see what format its actually outputting?
Click to expand...

Monstieur said:
How? There is absolutely no mention of the downsampling.

Based on the appearance of the image, the GPU is indeed sending a true RGB signal. 4K 120 Hz RGB internally downsampled with PC icon looks identical to 4K 60 Hz RGB internally downsampled without PC icon. With PC icon, 4K 60 Hz RGB is not downsampled.
Click to expand...
 
Where do you view/change the colour settings in the NVIDIA control panel? For 4:4:4 or 4:2:2 etc?
 
domenic said:
Take a look of this video showcasing the 3080 along with a 48 CX (link takes you to 4:23 timestamp). Sorry for the noob question but what's the difference between setting the output color format to RGB vs 4:4:4 vs 4:2:2 in the NVIDA interface? Does RGB = 4:2:2? If so why present both options?

Click to expand...


Hmm, so he was able to select 120 Hz @ 10-bit with RGB. Interestingly, it looked like 12-bit and YCbCr444 were available in the drop-down boxes as well but he didn't try them. I suppose the only question is if the TV downsamples internally, and how noticeable that is. Personally, I don't care and am definitely in for a 3000 series card...I'm currently using 120 Hz with 4:2:0 and find it to be perfectly acceptable using it 8+ hours a day for work etc. but I would certainly welcome an improvement to small red text when I encounter it (error messages in PowerShell can be particularly difficult to read, but I only use PS occasionally).

lludson said:
Where do you view/change the colour settings in the NVIDIA control panel? For 4:4:4 or 4:2:2 etc?
Click to expand...

Open NVCP and on the left, it's in the "Change resolution" tab under the Display group.
 
Lateralus said:
Hmm, so he was able to select 120 Hz @ 10-bit with RGB. Interestingly, it looked like 12-bit and YCbCr444 were available in the drop-down boxes as well but he didn't try them. I suppose the only question is if the TV downsamples internally, and how noticeable that is. Personally, I don't care and am definitely in for a 3000 series card...I'm currently using 120 Hz with 4:2:0 and find it to be perfectly acceptable using it 8+ hours a day for work etc. but I would certainly welcome an improvement to small red text when I encounter it (error messages in PowerShell can be particularly difficult to read, but I only use PS occasionally).
Click to expand...

If it's a hardware limitation rather than something fixable via firmware then it would be a dealbreaker for me. Removing half of the chroma~color information is not acceptable.
Hoping it's fixed in a LG firmware update by november along with nvidia fixing the broken hdmi 2.1 VRR with driver update(s).

elvn said:
RGB is 444. YCbCr 444 just has to be converted to RGB.
Click to expand...

https://www.reddit.com/r/hardware/comments/8rlf2z/psa_4k_144_hz_monitors_use_chroma_subsampling_for/
Since RGB-format images don't have luma or chroma components, you can't have "chroma subsampling" on an RGB image, since there are no chroma values for you to subsample in the first place. Terms like "RGB 4:4:4" are redundant/nonsensical. RGB format is always full resolution in all channels, which is equivalent or better than YCbCr 4:4:4. You can just call it RGB, RGB is always "4:4:4".
Click to expand...

Also, chroma subsampling is not a form of compression, because it doesn't involve any de-compression on the receiving side to recover any of the data. It is simply gone. 4:2:2 removes half the color information from the image, and 4:2:0 removes 3/4 of it, and you don't get any of it back. The information is simply removed, and that's all there is to it. So please don't refer to it as "4:2:2 compression" or "compressed using chroma subsampling" or things like that, it's no more a form of compression than simply reducing resolution from 4K to 1080p is; that isn't compression, that's just reducing the resolution. By the same token, 4:2:2 isn't compression, it's just subsampling (reducing the resolution on 2/3 of the components).
Click to expand...

lludson said:
Where do you view/change the colour settings in the NVIDIA control panel? For 4:4:4 or 4:2:2 etc?
Click to expand...

Just to reiterate, what people are saying is that even when you send a RGB signal (4:4:4) to the TV with the drivers reporting it being sent, the CX OLED TVs at 120Hz 4k on hdmi 2.1 are internally downsampling to lower chroma which looks just like the non-pc icon input mode of the TV at 60hz (which doesn't accept and show RGB).
 
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@Lateralus - thank you.


I am having a hell of a time getting these 3 CX's to all work on my Titan Pascal XP SLI rig, using the NvidiaCP.

Center screen on HDMI does 4k in the "PC" Section at 120hz - NO HDR
Left and Right on HDMI/Club 3D adapter do 4k in the "ULTRA HD" section at 60hz. - Both run in HDR

My screens go black if I try to set the left and right on HDMI/DP @120hz in the PC section of resolutions.

I unplugged one and get a really corrupt looking screen (tried it on the right one).

I just don't know what the hell to do. And these PASCAL TITAN XP's are 4 years old. I have no idea if I am struggling because of that. And if the 3090 I want to move to will let me do this alright. I am using great cables...

To have my three screens as below totally sucks ass.

4k 60hz HDR || 4k 120hz no HDR || 4k 60hz HDR


EDIT: Whelp.
- I can do all 1080p 120hz HDR.
- All at 4k 120hz is not yet possible for me and my Pascal Titan XP's....
 
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Great news to hear that broken VRR is just an nvidia driver thing that will probably be fixed with a hotfix driver. As for the whole 422 downsampling thing, eh I never even use my CX for desktop use so it's been sitting at 120Hz 420 on my 2080 Ti since July 1st so that doesn't bother me. I just want to finally be able to play at 4k120Hz VRR with HDR on.
 
I will tell all of you guys straight up, at least with the C9 and the RTX 3080, there has to be a few very serious bugs with the display driver, Windows 10, and or the LG and or firmware that will have to be patched. Either one or all of them, I have no clue where to start.

It's so annoying I'm seriously considering pulling my new RTX 3080 video card for now. Actually, I probably will unless I can find a fix online somewhere.

The "Instant Game Response is Launched" message is constantly popping up at random several times a minute which blacks out the screen for a good second. Super annoying. I am also exciting games only to be greeted with a distorted glitched out 4K desktop that I cannot recover from OR the game launches to a black screen that I cannot recover from.

I'm into day 2 since buying the RTX 3080 and I've been forced to reset / reboot my PC at least 15+ times

Can someone please tell me if there is a method to FORCE "instant Game Response" to just stay the FUCK on, I don't need it switched on or off automatically, I don't need a god damn notification message in the corner of my screen each and every single time. No reason that I can't just go into my settings and see if this feature is on or off. Also, where is the dark theme for the LG menu system? I thought GUI people were a specialized position within these teams that design, develop and build these TV's. Seriosuly dropping the ball here.
 
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I have the 77", not the 48", but it's the same TV model so I'm gonna post here. Anyways I'm pretty annoyed that these TV's only support G-Sync with 16xx and 20xx cards, because I'm under the impression it's an artificial limitation. I have been enjoying 4k 120z with lesser color chroma and it's actually been pretty sweet, but I would love me some G-Sync as I can still see screen tearing on everything. I suppose it's my fault for not reading the fine print on the product page for the TV, but since I've already used various G-Sync monitors with these card, I wouldn't intuitively think that I wouldn't be able to use G-Sync without the newest cards.
 
From AVS Forum thread:
https://www.avsforum.com/threads/2020-lg-cx–gx-dedicated-gaming-thread-consoles-and-pc.3138274/post-60111929


laxu said:
It doesn’t seem to be a bandwidth issue because it happens at 8-bit color as well and 1080p 120 Hz.
Click to expand...
André Fagundes said:
Just tested with 1080p and happened as you said, only 59 and 60hz displayed 4:4:4 but for 120hz, 100hz and even lower refresh rates like 50hz and 30hz were displayed at 4:2:2. Damn. Is there a link were we could report this and LG actually listen to it? If someone like Linus Tech Tips did a video criticizing this issue I bet LG would get this fixed in a week.
Click to expand...
 
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