OLED & G-Sync & VRR = In game Flickering solution

High Hz on OLED produce excellent strobeless motion blur reduction with fast GtG pixel response. It is easier to tell apart 60Hz vs 120Hz vs 240Hz on OLED than LCD, and more visible to mainstream. Includes WOLED and QD-OLED displays.
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shasoosh
Posts: 1
Joined: 05 Aug 2021, 05:30

OLED & G-Sync & VRR = In game Flickering solution

Post by shasoosh » 05 Aug 2021, 05:55

Hey Guys,

I got my 3080 about a week ago and had a LOT of flickering issues with my LG OLED CX.
Resolution is 4K, G-sync & IGR are ON.
I've tried a few things suggested in the forum, in the G-Sync 101 here and on reddit such as limit FPS to Refresh rate - 3, disable Connectivity in the TV, change HDMI cord to a certified one, change brightness etc'.
Nothing helps. Even while changing brightness to 40 on the TV, I can still see the flickering.

The only thing that eliminates the flickering completely is to disable G-Sync or IGM.
The flickering were so bad that I had to turn IGR off in order to play without being distracted.

Btw, I'm only talking about brightness flickering that happens in-game. I don't care about the ones that happen in menus.

SO far I've discovered two interesting things that I couldn't find a reference to:

The first, apparently there is a difference between capping FPS in NVCP vs RTSS.
Capping the FPS from NVCPL will somewhat cap them BUT will not be spike proof. So for example capping to 117FPS will still present a millisecond spikes to 200-300 etc'.
RTSS however will not introduce these spikes and will present only the drops.
The end result is that capping with NVCPL will introduce a lot more flickering vs capping with RTSS.


Second, which was for me the main culprit, is a software running in the background called "Rainmeter" which introduced unbearable flickers because of FPS spikes and FPS fluctuation.

No idea why it is happening. I guess the fact that it polls the GPU every few ms causes FPS spikes.

I've tested this so far on two games, Shadow of the Tomb Raider and RE:Village and the in-game flickering are gone! Completely!

Check out the difference in these FPS graphs.
Rainmeter running in the background:
enAUdpl.jpg
enAUdpl.jpg (1.31 MiB) Viewed 9927 times
Rainmeter NOT running in the background:
yirUjoU.jpg
yirUjoU.jpg (1.32 MiB) Viewed 9927 times
This pretty much explains it why some people hardly notice flickering while others can't ignore it.

I guess there are other software that can cause these. If you know of any, please post them here.

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jorimt
Posts: 2481
Joined: 04 Nov 2016, 10:44
Location: USA

Re: OLED & G-Sync & VRR = In game Flickering solution

Post by jorimt » 07 Aug 2021, 10:24

The VRR flickering on the LG CX (which I also have) is well known, and is a hardware limitation on the panel due to slight gamma variances between each "Hz" with any rapid and/or large fluctuation of refresh "rate" during VRR operation.

The more sporadic the frametime performance, the worse the flickering will be.

The only way to avoid it on this display in games with sporadic frametimes is to keep the frametime performance as steady as possible by ensuring the framerate is limited by the FPS cap at all times (RTSS, particularly, as it limits by frametime), and not by the system, be that from GPU or CPU-limitation, as well as what you mention; I.E. ensuring no other external program negatively affects frametime performance.

Basically, anything that creates sporadic frametime performance and/or wide swings in framerate will cause VRR flicker on this display.
(jorimt: /jor-uhm-tee/)
Author: Blur Busters "G-SYNC 101" Series

Displays: ASUS PG27AQN, LG 48CX VR: Beyond, Quest 3, Reverb G2, Index OS: Windows 11 Pro Case: Fractal Design Torrent PSU: Seasonic PRIME TX-1000 MB: ASUS Z790 Hero CPU: Intel i9-13900k w/Noctua NH-U12A GPU: GIGABYTE RTX 4090 GAMING OC RAM: 32GB G.SKILL Trident Z5 DDR5 6400MHz CL32 SSDs: 2TB WD_BLACK SN850 (OS), 4TB WD_BLACK SN850X (Games) Keyboards: Wooting 60HE, Logitech G915 TKL Mice: Razer Viper Mini SE, Razer Viper 8kHz Sound: Creative Sound Blaster Katana V2 (speakers/amp/DAC), AFUL Performer 8 (IEMs)

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