PG32UCDP - 420 nit cap?

[AjayLikesGaming]

Hi there,

I'm currently running into an issue with the HDR modes on this monitor. When attempting to calibrate in Windows HDR Calibration, it will never surpass 420 nits. This happens regardless of mode - there are no visual differences whatsoever when swapping between Gaming, Console, and Cinema HDR modes.  

In this video, you can see that there should be changes - https://youtu.be/FYLMymA60KU?t=469 - and when I first got this monitor, it seemed to take a lot of driver uninstalls and reinstalls to even reach this point. Now I can't seem to get there at all - I am stuck with 420 nits for reasons I do not understand. 

I'm running firmware MCM106 presently, but experienced this on 103 too. I see so many reports of this issue online but no solution?  

[Aureliannn_ROG]

Hi @AjayLikesGaming ,

Thank you for your inquiry. 

To better understand the issue of the display's brightness being limited, please provide us with the following information:

1. Problem start time: You mentioned that the brightness is limited to 420nits. Did this problem exist when you received the device?
2. Test screenshot: Can you provide relevant test screenshots so that we can understand how you determined that the brightness is limited to 420nits? Please specify the part of the screenshot that shows the brightness as 420nits.
3. Factory reset: Have you tried restoring the display to factory settings? Can the problem be resolved after restoring factory settings?
4. Connection cable testing: Have you tried testing with different connection cables? Do the same problems occur with different connection cables?

At the same time, please provide your display product serial number via private message so that we can confirm the detailed information of the product.

Please kindly confirm the above information. Thank you.

[AjayLikesGaming]

I'll try to answer these questions as fully as possible @Aureliannn_ROG 

1. Yes, it's always been an issue, but one I did manage to make work after playing around with drivers for a long while. The issue has since returned in recent months and I cannot for the life of me get it working again. 

2. Here is a video of the issue (LINK). As you can see, Windows HDR Calibration is capping out at 420 nits despite the display driver reporting the maximum as the advertised 1000+. When swapping between all the various HDR modes that should produce different tonemapping results, nothing changes. Even when swapping to the 400 nit mode, the results are completely identical. 

3. Correct, a factory reset has been attempted to no avail. 

4. Yes, the issue is present with all cables (including both DP and HDMI) 

[AjayLikesGaming]

I've done some troubleshooting and can provide an update on this strange, but still unsolved, mystery. 

I ran Display Driver Uninstaller (DDU) and wiped everything. When I boot into Windows and install the drivers again, the HDR functions as intended. The calibration tool shows results all the way up in the 1200 range as it should.

However, upon restarting my PC and finalising the install, it once again returns back to the 420 nit cap. Frustrating!

My hunch was that maybe Windows was automatically installing something upon restart, so I disabled its ability to install any drivers. Alas, the issue still persists.

I'm now wondering if there is some kind of combability issue between Nvidia and this monitor? I'm just confused by this all. 

Really tearing my hair out and hoping someone knows what on earth is going on? I see reports about this under various YouTube videos but no answers 😕 

[Cheeseballz]

I've been having the exact same issues with the same monitor with the calibration tool, and the HDR colors also look way off in game when enabled. I also have an RTX 4090 This wasn't happening until recently, so am unsure if it has something to do with Nvidia drivers or some update with Windows but it's been frustrating because I can't figure it out. 

[markob53]

As i understand it, the only reason to use the Windows HDR Calibration tool is to create a profile to tell games and applications how many nits your monitor is capable of (as well as set your desired saturation) it isn't meant to physically change the appearance or brightness of the monitor.

If the monitor by default is already reporting the right amount of nits (so in your case 1316) then you don't have to run the calibration tool or you can run it and ignore when the pattern disappears and simply set it to 1316 and your desired saturation.

I think the reason the tool can report incorrect nits or cap at a smaller value is that the size of the white box is bigger than the area the max amount of nits the monitor can display (i.e bigger than 1% window) so it caps at a much small value, if that makes sense.

So just do what i said in paragraph two and enjoy your monitor.

[AjayLikesGaming]

I'm afraid that's not how that works. The HDR Calibration tool doesn't magically change your monitor's capabilities, but it exists to create a tonemapping curve accurate to what it can produce. Without it, highlights will clip. It's why the tool exists in the first place. You cannot set it higher than what those patterns show or everything will be blown out. The mismatch is an issue, and as evidenced in the initial review video I linked and my own experience when I can get it to work, there is a dramatic difference.  

The reason the tool is reporting wrong is because something is broken presently. It is clipping at 400 nits across all window sizes. You're not incorrect that obviously brightness will vary across window sizes but that's why that tool exists. It's generates you a Min Lum, Max Lum, and a Max FFL. 

Putting all that aside, we can confirm it is 100% broken because the Console Gaming HDR mode, which uses HGIG doesn't respond to anything at all. All modes behave the same same when they should be all be tonemapping differently. 

As it stands, you literally cannot compromise in any way. You are stuck with 400 nits or nothing. What the EDID reports is irrelevant.  

[Cheeseballz]

I tried re-installing Windows last night for the heck of it (I didn't want to because I'm lazy but did anyway) and now for whatever reason it seems to work now where in the calibration tool you can go past 400nits in gaming and cinema HDR mode etc. and it seems to calibrate properly. Don't know if I was just dumb but maybe it was some sort of software issue on my side?

Also yeah I agree that you wanna run the calibration tool...I noticed that if you don't run it and create a profile then HDR looks weird on content on this monitor.

[AjayLikesGaming]

That's interesting. Was it a full Windows install or did you manage to do a Windows repair? 

I agree it's likely some kind of Windows software related issue. I tried my monitor on my old machine and it functioned as intended. 

[markob53]

But how can i accurately calibrate my monitor to it's maximum potential if the size of the window in the tool is bigger than 1%? This will stop me from seeing the brightest highlights in games. 

Also for some reason my results for FFL and Max Lum are nearly identical, which doesn't seem right considering the former is a much brighter window. On my PG27AQDM the pattern dissappears at 880 nits and this is the case no matter what HDR mode i use, however (i use Console mode) i do seem to remember there was a time where the other modes clipped at much higher values.

But up until now i've been setting my Max Lum at a higher values knowing my monitor is capable of more (i think reviews say around 930 nits) and i've seen others saying they do the same, surely if i want the brightest highlights i have to do that?