OLED 240hz lg-27gr95qe-b and G-Sync Brightness Flicker

[KanjiEater]

I'm using a 60+fps build for the first time & running into some of the normal issues with G-Sync it would seem.

Monitor: 27GR95QE-B https://www.lg.com/us/monitors/lg-27gr95qe-b
OS: win11
GPU: 4070TI
CPU: 13900ks
Build Specs here: https://pcpartpicker.com/b/6QGqqs


My Issues:
My main issue with enabling G-Sync is the brightness flicker on frame drops.
Games like Horizon Zero Dawn work great - no flicker, smooth frame rates.
A. Emulators like Yuzu struggle to keep a solid 60fps depending on the game & the internal resolution.
B. If I run G-SYnc in windowed / FS mode, apps that are poorly optimized for G-Sync start to flicker. (FluentSearch is the program I ran into this issue with)


Things I've tried:
1. I've run through the G-sync 101 (and probably need to read through it again)
2. Turned on V-Sync in NCP & off in games.
3. Tried turning on G-Sync for Windowed & Full Screen mode - causes Issue B.
4. Turned on Full Screen mode only - causes issue A.
5. Tried Setting my monitor range from 48 to 70-240hz to fix A & B via CRU, to fix "low-hz flicker" I realize as I'm writing this that that's not the same as brightness flicker viewtopic.php?f=5&t=1627&start=10#p71283 I also tried setting my monitor range from 1-240hz (obviously this didn't help either)
6. Turning G-Sync off fixes all brightness flickering
7. I used NCP global frame limiter to limit to 237fps

Questions:

1. What should I do for poorly optimized or programs I can't run above my monitors refresh rate?
2. Should I turn it on only for fullscreen apps?
3. If so, is it possible to use Nvidia Control Panel to disable G-Sync on a per app basis? Or should I default to g-sync off, and enable it on a per app basis.
4. How should I play 60fps games with this monitor: Should I always just have 70-240hz locked in like the link above mentioned even for games that are 60fps? Should I be limiting to 57fps?

Thank you for the resources here! I'd love to see a YouTube series on this sort of information.

[RealNC]

Some displays will flicker when using VRR and FPS gets too low, or if there's a very wide FPS variation. Not much you can do about it. Some displays are just better at this than others.

As for specific programs that don't actually need VRR, you can disable it in the program's profile in the nvidia control panel. If it's not already listed you can add its executable, and set "monitor technology" to "fixed refresh." NVidia already ships a ton of profiles with g-sync disabled for various software out there, but fortunately you can also add your own profiles.

[KanjiEater]

Thank you for the answers!

So
1. Set their individual Nvidia profile Monitor Tech to fixed
3. Yes, Monitor Technology setting in NCP
I still need to figure out 2 & 4.

I'm guessing 2 & 4 would come down to if the brightness flicker happens or not. I'd love to know whether I should just drop the minimum allowed framerate from 48-240hz to something like 1-240hz for 60fps games. But it's unclear what the minimum frequency would be to avoid the flicker. Any ideas on what to set that to for lower fps games?

[RealNC]

I'm guessing 2 & 4 would come down to if the brightness flicker happens or not. I'd love to know whether I should just drop the minimum allowed framerate from 48-240hz to something like 1-240hz for 60fps games. But it's unclear what the minimum frequency would be to avoid the flicker. Any ideas on what to set that to for lower fps games?

Usually you set it higher, not lower, in order to prevent the display from going too low. If you set it to, say, 80-240, than what that means is that for 60FPS, the monitor should do LFC at 120Hz. If that doesn't fix it, then I don't know of anything else that could, other than getting a display that's better at VRR

[KanjiEater]

I'm guessing 2 & 4 would come down to if the brightness flicker happens or not. I'd love to know whether I should just drop the minimum allowed framerate from 48-240hz to something like 1-240hz for 60fps games. But it's unclear what the minimum frequency would be to avoid the flicker. Any ideas on what to set that to for lower fps games?

Usually you set it higher, not lower, in order to prevent the display from going too low. If you set it to, say, 80-240, than what that means is that for 60FPS, the monitor should do LFC at 120Hz. If that doesn't fix it, then I don't know of anything else that could, other than getting a display that's better at VRR

Oh interesting. Just to make sure I'm following, for 60 fps w/ brightness flicker, we actually want it to do LFC w/ G-sync at 120fps rather than fixed refresh rate w/ proper 60fps?

[jorimt]

My Issues:
My main issue with enabling G-Sync is the brightness flicker on frame drops.
Games like Horizon Zero Dawn work great - no flicker, smooth frame rates.
A. Emulators like Yuzu struggle to keep a solid 60fps depending on the game & the internal resolution.
B. If I run G-SYnc in windowed / FS mode, apps that are poorly optimized for G-Sync start to flicker. (FluentSearch is the program I ran into this issue with)

LG OLED VRR flicker is its own beast. If you're talking about the near-black flicker (if not, that's new for these panel-types, to my knowledge), it is caused solely by frametime variances, not LFC range, etc, like with VRR LCD monitors.

Long story short, the worse or more sporadic the frametime performance is in a game, the worse the near-black OLED VRR flicker will be.

The only way to avoid this on current-gen LG OLED panels during VRR operation is to use an external limiter like RTSS to set an FPS limit that can be sustained 99% of the time in the given game.

I.E. you want the RTSS limit to be the framerate's limiting factor the majority of the time. As long as it is, RTSS will stabilize frametime performance, which should reduce the near-black flicker to a minimum.

[KanjiEater]

My Issues:
My main issue with enabling G-Sync is the brightness flicker on frame drops.
Games like Horizon Zero Dawn work great - no flicker, smooth frame rates.
A. Emulators like Yuzu struggle to keep a solid 60fps depending on the game & the internal resolution.
B. If I run G-SYnc in windowed / FS mode, apps that are poorly optimized for G-Sync start to flicker. (FluentSearch is the program I ran into this issue with)

LG OLED VRR flicker is its own beast. If you're talking about the near-black flicker (if not, that's new for these panel-types, to my knowledge), it is caused solely by frametime variances, not LFC range, etc, like with VRR LCD monitors.

Long story short, the worse or more sporadic the frametime performance is in a game, the worse the near-black OLED VRR flicker will be.

The only way to avoid this on current-gen LG OLED panels during VRR operation is to use an external limiter like RTSS to set an FPS limit that can be sustained 99% of the time in the given game.

I.E. you want the RTSS limit to be the framerate's limiting factor the majority of the time. As long as it is, RTSS will stabilize frametime performance, which should reduce the near-black flicker to a minimum.

Thanks for the responses. I think this is the near black level flicker. Are you saying black level flicker and LG Oled vrr flicker are different?

For now, I think I will just keep g-sync on for fullscreen programs by default, as windowed ones, even chrome can start the flicker - and I'd rather not start white listing what programs to turn g-sync off. I did see this topic where you both covered it pretty well why Fullscreen is going to be better in general. viewtopic.php?t=10099

I would like to enable some windowed games to use g-sync but it seems that if you set the global to fullscreen only there isn't an nvidia setting to override it per game WHILE it's windowed. Any ideas how to run a game windowed with gsync while the global setting says fullscreen only?

[jorimt]

Thanks for the responses. I think this is the near black level flicker. Are you saying black level flicker and LG Oled vrr flicker are different?

I'm saying the causes and nature of VRR flicker are different for OLED than they are for LCD.

You had said "brightness" flicker, which is more common on LCD, whereas near-black flicker is typically exclusive to current-gen OLED, but it now sounds like we're talking about the same thing in this case (near-black flicker), so it was just semantics.

Again, for OLED, you need to ensure rock solid frametime performance to reduce its particular form of VRR flicker. It's what I do on my LG CX.

The fact that you weren't seeing the flicker in some games just meant they had above-average frametime performance out-of-box, like Horizon (which I also own), where the developers have prioritized pre-compilation of shaders and minimal asset loading stutter during traversal.

For now, I think I will just keep g-sync on for fullscreen programs by default, as windowed ones, even chrome can start the flicker - and I'd rather not start white listing what programs to turn g-sync off.

I would like to enable some windowed games to use g-sync but it seems that if you set the global to fullscreen only there isn't an nvidia setting to override it per game WHILE it's windowed. Any ideas how to run a game windowed with gsync while the global setting says fullscreen only?

G-SYNC mode is typically not recommended for desktop apps, in part, because of some of the issues you're seeing.

See entry #5 of my Closing FAQ for how to apply G-SYNC borderless/windowed selectively per app (where needed) via Nvidia Inspector:
https://blurbusters.com/gsync/gsync101- ... ttings/15/