ASUS PG329Q OSD GAMMA INCORRECT & STUTTER/JUDDER/TEAR AT VSYNC & GSYNC

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Hey everyone,

So I got myself the ASUS PG329Q as my old Samsung 27" 120hz died. Had a colour banding issue pretty much straight out of the box where a distinct vertical line shifted the colour so 1/3 of screen had a different shade. RMA'd the unit and ASUS's authorised repair centre replaced the panel.

The new panel fixed the colour banding 100%, but noticed couple of new issues.

ISSUE 1 – GAMMA INCORRECT

At Gamma default OSD setting of 2.2 images looked a bit washed on the brighter scenes/images so I measured the default and it seems off by quite a bit (and so is the other settings of Gamma 1.8 and Gamma 2.5 by roughly the same amount of around +/- 0.22) as measured by i1Display Plus device on Displaycal software.

I’ve done 2 kinds of test using Displaycal:

1. “Report on uncalibrated display device” using the following menu in Displaycal -

Tools > Report > Report on uncalibrated display device

I’ve included video of how I measured it (Google Drive link below with all files). The reports are the .log files. As you can see OSD Gamma 1.8 setting gives avg reading of 1.58 and OSD Gamma setting of 2.2 gives avg reading of 1.95. Just for reference, the Original Panel was giving a reading of around 2.15.

2. Also did “Measurement Report” under the “Verification” tab.

The reports are titled “Measurement Report ….” .html files. I’ve tested monitor OSD Gamma 2.2 setting under the OSD Menu > Gaming > GameVisual > “sRGB Mode” and “User Mode” with default settings.

Included screenshot of settings used titled “Measurement Report Settings… .jpg”. If this is not the correct settings to test default monitor settings please let me know and I’ll do a re-test (only possible for repaired unit though).

Tested on 2 systems – (System 1 using GTX980SLI) and (System 2 using RTX3070).

Also included is “Measurement Report (ORIGINAL PANEL)” which was the measurements from the unit before it was RMA’d and panel replaced because of colour banding issue.

This was to mainly test the Gamma value tracking against the correct sRGB values. You can see the measured Gamma values compared to the nominal sRGB Gamma value across the Gray-Scale range under the “Overivew” section as well as the ‘spot’ Gamma graph when you scroll down.

As you can see the ORIGINAL PANEL more or less tracked Gamma 2.2 (confirmed by attached “Original ASUS Calibration Test Report” that came with the monitor) not dipping below 2.0 especially in the brighter range around 90%. Whereas the new panel is tracking well below 2.0 for majority of the range, going as low as 1.8 at the brighter range around 90%.

If I try calibrate with ICC profile there’s banding issues and darks grays get lifted too much. ICC profile isn’t used by games either, so colour looks oversaturated and off with the gamma not tracking close to 2.2.

Also tried adjusting saturation to make it sRGB-like then calibrating and ICC profiling but then the colours gamut is clipped and aren’t close to sRGB anymore (they look more duller than normal sRGB).

That’s why I want to turn down the OSD saturation to sRGB-like levels and only calibrate to get the white balance right without using ICC profile while using the default OSD Gamma of 2.2. But with the OSD Gamma being off by more than 0.2 the image doesn't look balanced. If I use OSD Gamma 2.5 it darkens by too much so it’s kind of in the middle of nowhere.

The monitor OSD sRGB mode is also tied to OSD Gamma 2.2 so looks a bit odd (the locked brightness setting doesn’t help either- would be nice if it was unlocked in the future). But this is just a side-note. Main thing is Gamma doesn’t seem to be tracking properly.

If additional Gamma settings could be added to OSD so that Gamma levels can be adjusted incrementally that would be a great fix so that pretty much any unit can be adjusted to a balanced level. Or if the current OSD Gamma 2.2 can be matched to give close to actual 2.2 value (as it was with original panel) that would also work.

Is there any way to adjust the Gamma so that it tracks closer to 2.2 like the original panel?

Just to reiterate, I tried calibrating and profiling using Displaycal with 'No corrections' and setting 'Tone curve' to Gamma 2.2 but the resulting profile clips the colour gamut as well so I don't get the colour pop from the monitor's wide gamut.


ISSUE 2 – STUTTER, TEARING IN VSYNC & GSYNC

Stutter/judder –

Seem to be having some kind of stutter/judder and the motions aren’t very smooth. First noticed it while playing DBZ Fighters where the images didn’t feel smooth compared to when I played on the monitor before it was RMA’d. I did a full clean install of the drivers after receiving the monitor back from RMA. Tried both on GTX980 (which I originally used) and RTX3070 systems.

Did several tests comparing 2 different systems, a laptop (Lenovo Yoga 720) and another monitor (AOC 2477W1M – old IPS monitor not gaming spec). You can notice there’s a clear difference between the PG329Q and the AOC monitor in the “Lagom Response Time Ghosting Test”, “LCD Display Motion Test Video”’, “Lexaloffle Screen Tear Test Video”, “Youtube Stutter Test Video” and the “Nvidia Sync Test” even with Vsync at 60-175fps.


Tearing –

Without Vsync I’m getting pretty bad screen tearing at 60fps as seen on “System 1 – Nvidia Sync Test…60fps” which wasn’t as bad before. But the main problem is using Gsync it’s still getting screen tears at 174fps in “Nvidia Pendulum..” & “Nvidia Sync” tests. I’ve noticed even 160-165fps getting tears using Gsync.

So, in summary,

• Tearing more than before in non-Vsync
• Stuttering (Vsync & Gsync) – especially worse in 60fps Vsync which definitely wasn’t there before.
• Tearing in Gsync at 175fps (even at 165fps)

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I’ve tried clearing out my Windows 10 display cache from registry, full reinstall of Nvidia drivers, made sure Gsync is ON (Note: I didn’t have Gsync when running the ORIGINAL PANEL on GTX980 as it’s not supported and it was still running fine. Without Vsync I had minor tears but definitely wasn’t any noticeable stutter). For the Gsync settings - I have Gsync turned on in 'Set up Gsync' in NVCP and 'Enable for fullscreen mode' and Vsync under 'Manage 3D setings' is set to 'Use 3D application setting'.

I don’t know whether this is Vsync/Gsync, or panel response time issue, or if it’s got something to do with Nvidia settings or my system (which hasn’t changed since Original Panel). However, I wasn’t having any stutter/tear issues when running in my GTX980 system – so leaning towards this NOT being a Nvidia setting issue.

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Here’s the Google Drive link with all the files:

https://drive.google.com/drive/folders/180o1b4UadGNloalp-nv7BlY0iO2APxLp?usp=sharing

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Test Sources –

Lexaloffle Screen Tear Test Video: https://www.lexaloffle.com/bbs/?pid=95092

Youtube Stutter Test Video: https://www.youtube.com/watch?v=hkN3PRPh00E

LCD Display Motion Test Video: https://www.youtube.com/watch?v=vigX3H7WX5Q

60fps Youtube Clock Judder Video Test: https://www.youtube.com/watch?v=k08MC8k8LlE

Nvida Sync Test & Nvidia Pendulum Test: Nvidia Pendulum Demo ‘Test Pattern’
https://www.nvidia.com/en-us/geforce/community/demos/

Lagom Response Time Ghosting Test: http://www.lagom.nl/lcd-test/response_time.php
 
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