Odd fluctuations with G Sync monitor

Talk about NVIDIA G-SYNC, a variable refresh rate (VRR) technology. G-SYNC eliminates stutters, tearing, and reduces input lag. List of G-SYNC Monitors.
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professorpig
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Joined: 30 Jan 2020, 15:41

Odd fluctuations with G Sync monitor

Post by professorpig » 30 Jan 2020, 15:48

Hello everyone, I've recently purchased a new G Sync monitor and I really love it - however, there's one issue I'm having that's very odd.

Sometimes, when I have a game that hovers between 60-80 FPS, I'll want to just lock it at 60 for a smooth experience. But whenever I set that game to 60, either through the application or through the NVidia control panel, my monitor's refresh rate doesn't follow. Instead, it will often oscillate between 110ish and 130ish, and the mismatch causes the screen to hitch a little bit or have uneven frame pacing (at least it feels that way to me). In general, whenever my framerate in any game goes into the 60's, my monitor's refresh rate shoots up into the 130's. This indicates to me that the monitor may be trying to double the framerate, as it's a 144hz monitor so any FPS under 72 would be capable of doubling. Does anyone know if this is an option I can change somewhere, either in Nvidia's control panel or somewhere else? It's not a huge deal, but I'd really love the option to play some games at 60 with my refresh rate locked there too. Any help would be appreciated!

Currently I have all my settings set to the standards given in https://blurbusters.com/gsync/gsync101- ... -settings/ and my monitor itself is an Asus VG278Q. My card is a GTX 1070, if that matters.

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jorimt
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Re: Odd fluctuations with G Sync monitor

Post by jorimt » 30 Jan 2020, 19:25

professorpig wrote:
30 Jan 2020, 15:48
Sometimes, when I have a game that hovers between 60-80 FPS, I'll want to just lock it at 60 for a smooth experience. But whenever I set that game to 60, either through the application or through the NVidia control panel, my monitor's refresh rate doesn't follow. Instead, it will often oscillate between 110ish and 130ish
Are you going by the monitor's built-in refresh rate meter (some have them, some don't), or an FPS meter (Afterburner, etc)? If it's the former, it could just be a misread, but if it's the latter, it sounds like it's triggering LFC a bit early.

This sort of thing doesn't happen on G-SYNC monitors containing hardware modules, but since yours is (officially) G-SYNC Compatible, VRR functionality is entirely software driven, so this could be related to the monitor's native FreeSync range (reported 40-144Hz) and/or driver implementation.
(jorimt: /jor-uhm-tee/)
Author: Blur Busters "G-SYNC 101" Series

Display: Acer Predator XB271HU OS: Windows 10 Pro MB: ASUS ROG Maximus X Hero CPU: i7-8700k GPU: EVGA GTX 1080 Ti FTW3 RAM: 32GB G.SKILL TridentZ @3200MHz

professorpig
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Re: Odd fluctuations with G Sync monitor

Post by professorpig » 30 Jan 2020, 21:00

Oh, interesting, I hadn't thought about that - I'm going by the counter that my monitor has built in, but running MSI lists my FPS as 60 like it should be. I have no idea if MSI would measure the frames a game spits out or the refresh rate. Could it be that the internal measuring stick on the monitor is messed up? It does seem to vacillate wildly at times. If that's the case, then it may be that the hitching is unrelated - running MSI I've also noticed that many of my games are hitting 100% on my CPU, which might be the root cause. Any clarification would be helpful, thanks!

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jorimt
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Re: Odd fluctuations with G Sync monitor

Post by jorimt » 30 Jan 2020, 22:20

professorpig wrote:
30 Jan 2020, 21:00
Oh, interesting, I hadn't thought about that - I'm going by the counter that my monitor has built in, but running MSI lists my FPS as 60 like it should be. I have no idea if MSI would measure the frames a game spits out or the refresh rate. Could it be that the internal measuring stick on the monitor is messed up? It does seem to vacillate wildly at times. If that's the case, then it may be that the hitching is unrelated - running MSI I've also noticed that many of my games are hitting 100% on my CPU, which might be the root cause. Any clarification would be helpful, thanks!
I've been seeing this more lately with users that have G-SYNC Compatible monitors that feature a refresh rate meter. It's possible that the majority of these meters were originally created and tuned to monitor native FreeSync implementation, and not necessarily G-SYNC Compatible implementation, and thus it is possible if you're not seeing these fluctuations on the system's FPS readout, that it may instead be a false positive caused by the monitor's meter.

If that is the case, and the hitching isn't due to your monitor kicking into the LFC range prematurely, but due to your system causing stutter, G-SYNC does not fix that form of stutter. G-SYNC only prevents sync-induced stutter due to repeat frames caused by framerate/refresh rate mismatch with FPS within the refresh rate.

G-SYNC does nothing for system-side stutter, the majority of which is caused by new frames not being output by the system for a frame or more at a time (spikes); if G-SYNC has nothing new to sync for the next frame, it must repeat the previous frame until a new frame is made available.

In other words, overall system performance and capability (along with the efficiency of the given game engine) do have an impact on how effective G-SYNC functionality can be in this respect (being system-side stutter) at any given time as well.
(jorimt: /jor-uhm-tee/)
Author: Blur Busters "G-SYNC 101" Series

Display: Acer Predator XB271HU OS: Windows 10 Pro MB: ASUS ROG Maximus X Hero CPU: i7-8700k GPU: EVGA GTX 1080 Ti FTW3 RAM: 32GB G.SKILL TridentZ @3200MHz

professorpig
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Re: Odd fluctuations with G Sync monitor

Post by professorpig » 31 Jan 2020, 01:07

Thank you so much for that explanation, it does seem like that's what's happening - I've spent the day doing some exploring and it looks like it may even be related to certain engines and/or publishers, perhaps there's something shared across their code that causes a false positive, or perhaps they're just poorly implemented. Either way, this helps a lot, and now I know where to focus my efforts. Thank you!

KrosaniTy
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Re: Odd fluctuations with G Sync monitor

Post by KrosaniTy » 18 Feb 2020, 05:33

Hello there professorpig, i have the same issue as well. i landed on this forum from google after searching for a solution for 3-4 hours. Surprisingly i happen to have the same GTX 1070 and monitor VG278Q and this is very weird. maybe you have an explanantion to this? or maybe this is normal? i dont know. i lock overwatch at 141 fps and my monitor refresh rate spikes to 144 and even goes to 130 for a milisecond and come back.. what did u do about this? did u find a root cause for this..

i used to have a gtx 1060 6gb last week and on this same monitor i DID HAVE A stable refresh rate with the fps. no issues i had.. but after switching to gtx 1070 i noticed this. so i guess this is a gpu not compatible with the monitor issue or something idk.

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