XG27AQDMG insane banding/posterization

[Lax567]

Hi All,

Just got a XG27AQDMG, and after some testing in games, I think something is seriously wrong.

I've got very noticeable posterization in dask-ish colors. For example here are two pictures from Genshin and Honkai Star rail :

The white circular shape is not supposed to be visible (it's a smooth gradient to the edges)The light cast is very unsmooth, I mean look at this

I'm running SDR with :

• user mode
• brightness 30
• uniform brightness ON
• shadow boost OFF
• gamma 2.2
• latest firmware MCM103

Tried :

• both DisplayPort and HDMI,
• going down to 60Hz
• made sure I'm running full RGB 10 bit
• increasing brightness, enabling shadow boost helps but it only makes the "white circle" bigger

That can't be normal, is my monitor faulty ?

Thank you

[Lax567]

Ok, so I did some more testing, and It seems that it is a combination of :

• GSYNC being enabled
• Games running at a capped framerate (in my case, 60 or 120)
• It also happens in HDR (I saw the issue with FF7 Remake capped at 120)

If I disable GSYNC, the issue almost completely disappears.

Furthermore, setting OLED anti flicker to high also alleviates the issue.

Is that a known issue ? Maybe worth escalating to the team @Aureliannn_ROG (sorry for the tag...) ?

[Lax567]

I think my unit is defective, there's no way this is normal

SDR, 60Hz, 35 brightness (uniform brightness on)

I've created a codepen to replicate the issue. Can someone try it out and see if you have the same thing ?

Thanks

[Aureliannn_ROG]

Hi @Lax567 ,

according to your issue, we have sent you the messege via PM box, kindly check and confirm.

Thank you.

[Lax567 · Accepted solution]

Sadly this did not resolve the issue.

For the record, here are my findings :

• it seems that running at a lower than maximum refresh rate causes gamma issues
• which, while bad in and of itself, also exacerbates the gradient issues (which I'm not sure are due to a defective unit or just poor near black gradient handling)

So basically you're left with 3 options :

• disable VRR to keep the monitor at 240Hz, but you then have stuttering in games
• set OLED anti-flicker to strong, which pretty much does the same thing, except for games that can run at a high enough framerate
• set "shadow boost" to "dynamic adjustment", which will kinda solve the gradient issue but NOT the gamma issue. It also takes a bit of time to adjust, which is jarring during scene transitions or basic alt-tabbing.

I've initiated a return procedure with the seller, since it's a dealbreaker for me. I wonder if it's a W-OLED only issue though ?

I find also quite baffling that no one is talking about this problem (except this post I found), which basically makes VRR unusable. I guess people were already diabling VRR due to the flickering ?

[VincentDM]

I set my monitor to the exact same settings that you mentionned, desptite Gamme set to 2.0 instead of 2.2 (cause some reviewers tend to say that it's a bit better).
I received that monitor yesterday, and already on the verge of returning it because of small but annoying issues.
I will try 60 fps locked games once I return home, to check if I experience similar results.
Not sure if it is a global OLED issue or an isolated case.

[Lax567]

If you could test it that would be great.

You can use this test pattern I made : codepen

You can try at different refresh rates and see if there is a difference (change the refresh rate in the Windows display settings).

[VincentDM]

Hey, just for the notice, I didn't had time to test this as much as I wanted, but it seem that I don't have the issue.
The thing is, on my photos, I saw that the Monitor was set to "Racing Mode", even though I remember switching it to User Mode a few times already. This is likely related to another big issue : This "600€" Monitor randomly reset it's settings after being woke up from Sleep...

For now, I can just say that I did not noticed severe banding issue on my unit. I've tried 60Hz, 240Hz, VRR On and Off, DSC On and Off, or Gamma 2.0 or 2.2. Typically setting most parameters to "Manual" whenever I can too, like selecting the DisplayPort InPut Mode instead of "Automatic".

But anyway, I will re-do the test more carefully tonight, by making sure that the User Mode is used, and will share another update.
Here's a photo for the time being :

[Lax567]

Well that looks like "severe banding" to me already ! My picture was overexposed and shot in the dark, so it's more visible there. But the main thing is how you can see a hard separation between some of the circles.

In a normal situation, each small circle should be really close to the ones next to it, you shouldn't see big jumps from one to the next.

Here we can make out basically 4 steps : the center which is white-ish, then a circle that has a strong blue tint, then a more dark purple one, then complete black. You'll also notice that these "zones" change in size when you change the refresh rate. I suggest you take two pictures, one at 240Hz and one at 60Hz. If your unit has the same issue as mine, there will be a big difference between the two. Also, to make the gradient more visible, you can take pictures in the dark and focus on the top left corner of the monitor, to overexpose the picture.

Here is a picture of my current VA monitor, for comparison (don't mind the colors, it's my phone that's compensating) : 

Looks a lot smoother, doesn't it ?

[VincentDM]

Yes, you're correct. I don't know what I was thinking and I half misunderstood - but that's indeed a banding problem.
However, It seem that activating the Display Stream Compression (DSC) in the Monitor settings, and 10 bpc colors in the NVidia Control Panel might have fixed the issue for me. (I understood that 240Hz and 10 bpc is only possible with DSC though).
But I'm testing some NoVideo_sRGB Clamp to fix the Black Crushes and I'm unsure If both are compatible.
Again, I will report my finding soon hopefully. I'm just lacking time to try more seriously at the moment. And testing things at 2 a.m. while half sleeping behind the computer isn't the smartest thing to do x)