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

[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)

[Lax567]

---

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.

---

For me it did not. In fact both were always enabled, but still, at 60Hz, the issue remained.

Now you're gonna ask why does it matter ? Well because consoles run at 60Hz and some PC games run at lower framerates too, so when you use GSYNC you run into the same issue.

[VincentDM]

So I tried again, and I can confirm that there is a difference between 8 and 10 bpc. However, I can't see the difference in you're picture. But on the Lagom Gradiant Test Page, I see less banding.
Again, I will continue to test things, but for the meanwhile, please have a look using various other source image to further check that issue.
I need to double check in games, but so far it looks OKay, even in 60 FPS locked games. At the very least, the only downgrade so far, compare to my previous IPS monitor, is the VRR Flickering. Which force me to disable the option from the OSD in Specific games.

[Lax567]

I already returned it so I can't do any more tests sadly.

I did however test with my Nintendo Switch before returning it, I had the same issues :

Have you increased the brightness or enabled shadow boost ? Because having low brightness + shadow boost OFF was the combination that made the issue most apparent.

[VincentDM]

I did not increased the Brightness (set to 30%) or use Shadow boost. I'm not sure, perhaps this is an issue with specific games or so.
I think that I'm gonna use the Monitor normally and decide if I return it or not depending on how it feels overall.
So far, I think that's I'll keep it. Hopefully someone else will reply to this topic regarding any possible banding issue.

[Lax567]

Well it's very possible that my unit was defective. At least I hope so, because otherwise that's quite a big issue in my opinion.

I didn't try my luck with a second unit so maybe we'll never know for sure...

As long as you're happy with it, it's all that matters

[AwenMilano]

hi there, i just use this monitor. wanna ask you guys, if we turn on power strip monitor was turn on itself?

i have behaviour to turn off my power strip when i go to sleep. but at morning when i want to turn on pc i start to turn on my power strip and monitor turn on itself, i already turn monitor  off  when i shut donw pc before.

sorry for out of topic, coz this confusing me. i use xg279q before and that monitor need manualy press power button for turn it on

[RealNC]

I get this issue when I forget to manually disable srgb clamping in novideo_srgb before switching to HDR mode. It can't do it automatically, you need to disable the "clamp" tickbox manually every time, also probably also set the dither option back to "default."

If I don't do that, the image looks posterized.