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G-SYNC 101: G-SYNC vs. V-SYNC w/FPS Limit

Published Jun 20, 2017 by in: G-SYNC

So Close, Yet So Far Apart

On the subject of single, tear-free frame delivery, how does standalone double buffer V-SYNC compare to G-SYNC with the same framerate limit?

Blur Buster's G-SYNC 101: Input Latency & Optimal Settings
Blur Buster's G-SYNC 101: Input Latency & Optimal Settings
Blur Buster's G-SYNC 101: Input Latency & Optimal Settings
Blur Buster's G-SYNC 101: Input Latency & Optimal Settings
Blur Buster's G-SYNC 101: Input Latency & Optimal Settings
Blur Buster's G-SYNC 101: Input Latency & Optimal Settings

As the results show, but for 60Hz (remember, a “frame” of delay is relative to the refresh rate), the numbers are relatively close. So what’s so great about G-SYNC’s ability to adjust the refresh rate to the framerate, if the majority of added input latency with V-SYNC can be eliminated with a simple FPS limit? Well, as the title of this section hints, it’s not quite that cut and dry…

While it’s common knowledge that limiting the FPS below the refresh rate with V-SYNC prevents the over-queuing of frames, and thus majority of added input latency, it isn’t without its downsides.

Unlike G-SYNC, V-SYNC must attempt to time frame delivery to the fixed refresh rate of the display. If it misses a single one of these delivery windows below the maximum refresh rate, the current frame must repeat once until the next frame can be displayed, locking the framerate to half the refresh rate, causing stutter. If the framerate exceeds the maximum refresh rate, the display can’t keep up with frame output, as rendered frames over-queue in both buffers, and appearance of frames is delayed yet again, which is why an FPS limit is needed to prevent this in the first place.

When an FPS limit is set with V-SYNC, the times it can deliver frames per second is shrunk. If, for instance, the FPS limiter is set to 59 fps on a 60Hz display, instead of 60 frames being delivered per second, only 59 will be delivered, which means roughly every second a frame will repeat.

As the numbers show, while G-SYNC and V-SYNC averages are close over a period of frames, evident by the maximums, it eventually adds up, causing 1/2 to 1 frame of accumulative delay, as well as recurring stutter due to repeated frames. This is why it is recommended to set a V-SYNC FPS limit mere decimals below the refresh rate via external programs such as RTSS.

That said, an FPS limit is superior to no FPS limit with double buffer V-SYNC, so long as the framerate can be sustained above the refresh rate at all times. However, G-SYNC’s ability to adjust the refresh rate to the framerate eliminates this issue entirely, and, yet again, beats V-SYNC hands down.

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3867 Comments For “G-SYNC 101”

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tenki
Member
tenki

Hello,

Thank you for your amazing guide, I am always following it very carefully and it was for me an immense help.

I have some questions though because I think that my setup is not 100% optimized

I have a desktop MSI QD-Oled 360hz 1440p, but I switch the refresh rate to 120hz because I usually do not play games more than 120fps , and my desktop gaming have a 5080 GPU and 9859X3D Ryzen.

For my questions:

– In NVCP I have like your guide and I have have v-synch set to default, gsync on only for full screen and LLM off. In game I have for sure V-sync on. I have no idea if it is better to cap the frame rate to 116fps with NVCP or RTSS because sometimes in game I have frequently shutterings when I cap, no matter what game is. Should also be cause because LLM Is off?

– Based on the question before, I don’t understand when it is the case to enable the limiter in game. Should it be a slider or more like a selectable option ( 60fps, 120fps, uncapped etc). I usually have every time uncapped, but is there a certain rule for it?

– sometimes in games I go over 120fps and oscillates every time , but not reaching 120fps or less. Though when I cap, I even go down ( not stable) , how is that possible? Should I not cap

– OLED on 240hz is flickering so much with G-sync, this is another reason why I put 120hz, but if you suggest to put 240hz and that’s it let me know.

Thank you so much in advance and sorry for my long comment!

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12 hours 56 minutes ago
jorimt
Author
jorimt

I have a desktop MSI QD-Oled 360hz 1440p, but I switch the refresh rate to 120hz because I usually do not play games more than 120fps

Not recommended, unless you have a very specific reason.

Otherwise, keep it at the highest supported physical refresh rate of your display. Else, it’s just slowing frame delivery with VRR, regardless of achievable framerate.

I.E. 120 FPS 360Hz VRR is lower latency than 116FPS 120Hz VRR.

I have no idea if it is better to cap the frame rate to 116fps with NVCP or RTSS because sometimes in game I have frequently shutterings when I cap, no matter what game is. Should also be cause because LLM Is off?

Based on the question before, I don’t understand when it is the case to enable the limiter in game. Should it be a slider or more like a selectable option ( 60fps, 120fps, uncapped etc). I usually have every time uncapped, but is there a certain rule for it?

Which framerate limiting method you use for what game/when is honestly down to situation and preference; they’re all very close where latency is concerned nowadays.

For reference, a “good” in-game limiter will only reduce overall latency by around 1/2 frame over RTSS, and it won’t usually achieve as stable of frametime performance.

Finally, FPS limiters nor VRR prevent all forms of stutter, so you’ll still experience unavoidable system-side stutter here and there, more or less depending on the game/engine.

sometimes in games I go over 120fps and oscillates every time , but not reaching 120fps or less. Though when I cap, I even go down ( not stable) , how is that possible? Should I not cap

If you mean your set limit doesn’t always keep frametime smooth, that’s because whenever your framerate naturally falls below the limit, or spikes above it, the limiter has no control over regulation in those instance; only when the average framerate is actually limited by the limiter is it in effect.

OLED on 240hz is flickering so much with G-sync, this is another reason why I put 120hz, but if you suggest to put 240hz and that’s it let me know.

OLED VRR flicker is entirely dependent on frametime performance; the more sporadic it is, the worse the flicker is, regardless of the physical refresh rate you have set.

As such, I’d suggest you use RTSS (since it tends to have the steadier frametime performance of most limiters available), and set the limit to an average your system can sustain 99% of the time in the given game.

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12 hours 24 minutes ago
tenki
Member
tenki

Thank you so much for the response

Not recommended, unless you have a very specific reason.

Otherwise, keep it at the highest supported physical refresh rate of your display. Else, it’s just slowing frame delivery with VRR, regardless of achievable framerate.

I.E. 120 FPS 360Hz VRR is lower latency than 116FPS 120Hz VRR.

So for this it is because of 10p colours on my Nvidia ( the range of colour in the setting as 240hz and 360 does not support it unless I set with my monitor with DSC enabled) . No idea if it is better to activate DSC and put 10p, disable it and put 8p at 360hz ( like you suggest) or any other combination scenario. Also Should I set it at 120 FPS at this point and keep enable gsync at this point ( I think I should keep enable and set It up like you said)

Which framerate limiting method you use for what game/when is honestly down to situation and preference; they’re all very close where latency is concerned nowadays.

For reference, a “good” in-game limiter will only reduce overall latency by around 1/2 frame over RTSS, and it won’t usually achieve as stable of frametime performance.

Finally, FPS limiters nor VRR prevent all forms of stutter, so you’ll still experience unavoidable system-side stutter here and there, more or less depending on the game/engine.

So you still suggest at this point to try the in game one to see how it runs and use RTSS as general limiter ( safe bet)? The only thing is if I can’t cap to 116 is it still viable?

If you mean your set limit doesn’t always keep frametime smooth, that’s because whenever your framerate naturally falls below the limit, or spikes above it, the limiter has no control over regulation in those instance; only when the average framerate is actually limited by the limiter is it in effect.

It is still strange that it can sustain an average frame limit, but produce more where I don’t set it T.T

OLED VRR flicker is entirely dependent on frametime performance; the more sporadic it is, the worse the flicker is, regardless of the physical refresh rate you have set.

As such, I’d suggest you use RTSS (since it tends to have the steadier frametime performance of most limiters available), and set the limit to an average your system can sustain 99% of the time in the given game.

Will I achieve this with trial and error and RTSS async or reflex limiter?

Thank you so much in advance for all the nice tips . I struggle so much with lagging and shuttering too much on any game , this is why and I upgraded my desktop to avoid it T.T

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9 hours 25 minutes ago
jorimt
Author
jorimt

So for this it is because of 10p colours on my Nvidia ( the range of colour in the setting as 240hz and 360 does not support it unless I set with my monitor with DSC enabled) . No idea if it is better to activate DSC and put 10p, disable it and put 8p at 360hz ( like you suggest) or any other combination scenario.

It can depend on the effectiveness of the HDR implementation on your monitor, but there is typically very little visual difference between 10-bit HDR and 8-bit HDR in PC games.

That said, if you’re looking to keep DSC disabled, then you should definitely at least keep your physical refresh rate at 240Hz instead of 120Hz when using VRR.

So you still suggest at this point to try the in game one to see how it runs and use RTSS as general limiter ( safe bet)? The only thing is if I can’t cap to 116 is it still viable?

If you’re picky about general latency, performance, and stutter, then you’re going to have to experiment with and tune each of your games. There’s no one-size-fits-all, set-and-forget method, unless of course you lower your standards and just accept inconsistent performance from game to game.

Every system has a performance “budget,” and if you exceed that budget, you start getting more performance issues. A.K.A. worse frametime performance, which will = more stutter.

In other words, perhaps both system “A” and “B” can run X game at a 120 FPS average, but system “B” is too weak vs. “A” overall to run it at that same average framerate as consistently.

Thus, even if your system can push a higher average framerate, it may not be worth the frametime inconsistency it causes to achieve it.

It is still strange that it can sustain an average frame limit, but produce more where I don’t set it T.T

Not sure if I’m misunderstanding you here, but the very reason for an FPS limit is to “limit” it below a number that would otherwise be higher without the limiter.

Will I achieve this with trial and error and RTSS async or reflex limiter?

If you’re trying to achieve the most stable frametime as to avoid as much OLED VRR flicker as possible, then you want to use RTSS Async, not the RTSS-level Reflex limiting method in this case.

As for how you should determine what to set the limit at in the given game, you can typically try to find the most demanding scene in the game while your framerate is uncapped, and then set your limit slightly below that.

For instance, if your game runs uncapped between 80 and 120 FPS, you’d set the limit at around ~75 for the highest possible consistency/stability, or if it’s between 125 and 270 FPS uncapped, you’d limit it around ~120, and so on…

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7 hours 29 minutes ago
asari7k
Member
asari7k

im still a bit confused. so i want to play dbfz at the lowest latency possible bc its a fighting game capped at 60 fps and im playing on a 240hz monitor. so whats better g sync + v sync (in ncvp) on with low latency mode on ultra or just disable g sync and v sync but low latency stil on ultra . bc ive seen some videos on youtube that tested capped 60fps games at higher refres rate and it gives lower latency so when i use g sync is automaticly caps it at 60hz so doesnt that just completly ruin the g sync vs v sync setup ?

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10 days 6 hours ago
jorimt
Author
jorimt
  1. G-SYNC off + V-SYNC off + 60 FPS + 240Hz physical refresh rate = will tear, lowest possible latency
  2. G-SYNC on + V-SYNC off + 60 FPS + 240Hz physical refresh rate = can tear, second lowest latency, as it sometimes won’t tear
  3. G-SYNC on + V-SYNC on + 60 FPS + 240Hz physical refresh rate = can’t tear, lowest possible tear-free latency
  4. G-SYNC on/off + V-SYNC on/off + 60 FPS + 60Hz physical refresh rate = highest latency, and should not be used in place of #1-3 on a higher refresh rate monitor

Basically, 60 FPS 60HZ VRR should be avoided over 60 FPS 240Hz VRR in your posed scenario.

The latter scenario means that, yes, while G-SYNC will refresh the display 60 times per second, each frame will scan in at a much faster ~4.2ms per at a 240Hz physical refresh rate vs. 60 FPS at 60Hz, where it will still refresh the display 60 times per second, but scan in each frame at a much slower 16.6ms per.

As for LLM Ultra, it reduces render queue latency separate of the sync latency that properly configured VRR reduces, but settings like LLM can only further reduce latency in all of the above scenarios if your GPU usage is 99% or above; if below 99%, it won’t reduce latency any further.

Thus, for DBFZ internally capped at 60 FPS, lowest possible latency on a 240Hz monitor is going to be G-SYNC off + V-SYNC off, lowest possible tear-free latency is going to be G-SYNC on + V-SYNC on, and LLM/Ultra will do nothing to reduce latency on top of that unless GPU usage is at 99%+…and that’s about it.

The rest is down to the inherent latency of your input device(s) and the performance of your ISP/internet connection (when playing online).

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10 days 5 hours ago
acecond
Member
acecond

Hey, I recently went back to gaming at a capped 60 FPS again using RTSS, and I have a 165 Hz monitor. With VRR enabled, what refresh rate should I set my monitor to for the smoothest and best 60 FPS experience? (Currently using 120 Hz with VRR)

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6 days 13 hours ago
jorimt
Author
jorimt

what refresh rate should I set my monitor to for the smoothest and best 60 FPS experience?

It should be set to the highest physical refresh rate your display supports for the lowest possible latency/fastest possible frame delivery.

With VRR, current physical refresh rate equals per-frame scan in speed; the higher the refresh rate, the faster the scanout, regardless of achievable average framerate.

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6 days 12 hours ago
acecond
Member
acecond

Makes sense. What if I’m playing older games or emulators that don’t play well with VRR, though? Should I still keep it capped at 165 Hz? (This is mostly why I play with 120 Hz on 60 fps.)

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3 days 11 hours ago
Mark Rejhon
Admin
Mark Rejhon

Emulators are self-capping at 60fps or 50fps, so no external cap necessary unless the internal emulator cap is very jittery.

Rare: Some people try to tame a very stuttery emulator with an external microsecond-precise cap (RTSS) set to about 0.01 to 0.1fps above your emulator’s self-cap.

Advanced complex dual cap approaches (main internal lag-saving cap / external stutter-reducer cap) are rare but are sometimes used for content that still stutter despites its internal cap. This is where the internal cap saves lag (but is very stuttery, like varying 58fps-62fps) and the other is a backup external cap that prevents stutter (makes the framepacing glassfloor). Always set the outer/backup frame rate cap higher than the inner/main frame rate cap. And always remember that 60fps-locked content is considered an internal cap already. Do not try the dual cap method unless you 100% understand everything else already (like 2nd year university after 1st year university pre-requisites). Dual caps will always make things worse unless you know what you’re doing. But it works in niche cases.

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2 days 10 hours ago
jorimt
Author
jorimt

There are few older games or emulators that don’t work with VRR, but for those very rare circumstances, it depends on if you’re then relying on standalone V-SYNC or no-sync for what I assume are games predominately hard-locked to 60 FPS or lower.

In that scenario, the highest possible refresh rate with no-sync is still optimal, but with standalone V-SYNC, yes, a physical refresh rate evenly divisible by 60/30 is technically preferable to a physical refresh rate that isn’t evenly divisible, even if the latter is higher than the one that is (165Hz vs. 120Hz in your case).

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2 days 15 hours ago
acecond
Member
acecond

Alright, thanks!

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2 days 11 hours ago
user2422
Member
user2422

Thanks for the comprehensive guide.

I have some questions on two topics:

1. If i have a 320Hz monitor with G-Sync enabled and play let’s say Apex Legends capped at 240 fps and can’t notice any obvious screen tearing, is there any reason to still use V-Sync in this scenario? From my understanding the latency in this scenario should be roughly the same whether V-Sync is enabled or disabled, so could it potentially have any other up or downsides? Also regarding this question, the increase in smoothness that is often shown with the optimal G-Sync configuration, is that due to the VRR or is it caused by the combination of G-Sync + V-Sync?

2. There seems to be a lot of situational use for some of these settings, so with all your knowledge and own personal experience over all those years now, what are you personally using when it comes to settings like LLM, Reflex, Windows VRR toggle, in-game vs driver V-Sync, what framerate limiters to use and what value to cap to?

Like3Vote Down 
15 days 3 hours ago
jorimt
Author
jorimt

If i have a 320Hz monitor with G-Sync enabled and play let’s say Apex Legends capped at 240 fps and can’t notice any obvious screen tearing, is there any reason to still use V-Sync in this scenario?

Not strictly, but even if you don’t see tearing with G-SYNC on + V-SYNC off, it’s there. How much it is noticed will be down to achievable frametime performance per game + the maximum refresh rate being used (the higher the refresh rate, the less noticeable tearing is, regardless of framerate) + individual user tolerances.

From my understanding the latency in this scenario should be roughly the same whether V-Sync is enabled or disabled, so could it potentially have any other up or downsides?

Only “downside” vs. G-SYNC on + V-SYNC on is the tearing.

Also regarding this question, the increase in smoothness that is often shown with the optimal G-Sync configuration, is that due to the VRR or is it caused by the combination of G-Sync + V-Sync?

The latter, mostly (complete lack of tearing).

There seems to be a lot of situational use for some of these settings, so with all your knowledge and own personal experience over all those years now, what are you personally using when it comes to settings like LLM, Reflex, Windows VRR toggle, in-game vs driver V-Sync, what framerate limiters to use and what value to cap to?

Entirely depends on the game, but typically, for me, less is more…

Beside G-SYNC being enabled, my global NVCP/Nvidia App settings are always at their defaults. I only tweak per game profile via Nvidia Profile Inspector, which usually consists of V-SYNC on, Prefer Maximum Performance, and a Nvidia Max Frame Rate limit if I’m not using the in-game or RTSS limiter (modern limiter choice is honestly down to preference and/or game limitations due to anti-cheat, etc).

As for the Windows VRR toggle, refer to:
https://devblogs.microsoft.com/directx/os-variable-refresh-rate/

This new toggle enables VRR support for DX11 full-screen games that did not support VRR natively, so these games can now benefit from your VRR hardware.

I personally only selectively enable it if a certain game absolutely requires it for VRR to engage.

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13 days 7 hours ago
user2422
Member
user2422

Thank you very much for the thorough reply, the detailed guide, and your years of service.

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13 days 2 hours ago
Iriodus
Member
Iriodus

So, 2 separate but related questions:

1) For games that use the Vulkan renderer, like Doom Eternal, should we be using borderless fullscreen or exclusive fullscreen?

2) Not sure if you’d know the answer to this one, but since Proton on Linux uses a DirectX-to-Vulkan translation layer, should people use the recommendation for question 1 above, or say if a game is DirectX11 before taking into account the DX-to-Vulkan translation do use Fullscreen/Exclusive Fullscreen as if we were on Windows.

For reference, I’ve replicated the optimal G-Sync setup on my Linux machine, and since switching I’ve just been doing “If it’s originally DX11 or lower? Fullscreen/Exclusive Fullscreen. If it’s originally DX12? I use borderless fullscreen”

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1 month 10 days ago
jorimt
Author
jorimt

For #1, It depends on if the given Vulkan game is using Independent Flip for its borderless mode.

In Windows on an Nvidia GPU, you can force this for Vulkan games by setting “Vulkan/OpenGL Present Method” to “Prefer layered on DXGI Swapchain” in the NVCP/App.

You can use a tool like PresentMon to verify the flip model in use.

As for #2, I can’t speak to it directly, since I’ve never used Linux/Proton for gaming.

Like3Vote Down 
1 month 9 days ago
Iriodus
Member
Iriodus

Thanks for getting back to me, so it sounds like borderless is preferred for Vulkan provided you’re using independent flip, as that Present Method setting keeps latency as low as possible, so duly noted.

Linux gaming overall has had less and more consistent latency on my end, better 0.1/1% lows, more so lately due to recent updates to Proton and Linux (more things in the pipeline as well), so I’m guessing I likely can just follow the recommendation for #1 and go borderless across the board for games that are translated to Vulkan (most of them) and for games that are already running Vulkan natively.

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1 month 9 days ago
ksydew
Member
ksydew

Sorry for posting so much but I have one last question, I just bought the acer Nitro XV275U F5BIIPPRX, it’s a free sync premium Pro monitor but isn’t g sync certified. It should still work with g sync no problem right? I have it turned on same usual settings, g sync indicator is working and on in the top right corner, but just want to make sure it’s fine? It seems like it is but I’m not the expert

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1 month 23 days ago
jorimt
Author
jorimt

Assuming it allows you to enable G-SYNC on the Nvidia CP/App, the indicator is working, and the refresh rate meter on your monitor is visibly fluctuating in game, then yes.

Like4Vote Down 
1 month 23 days ago
ksydew
Member
ksydew

Okay I may have just figured out lol, but I looked online and someone said that nvidias drivers sometimes kick in LFC at 60fps and lower for some reason, so I capped to 65 and the OSD now reports 65 solid and barely moves/changes and when it does it’s only between 64/66. I wonder if this entire time on my old monitor I had lfc kicked on and never realized it because it didn’t have a OSD that reported its vrr. Either way it seems I’ll just have to move my fps cap to 65 from now on… so no biggie

Like2Vote Down 
1 month 23 days ago
jorimt
Author
jorimt

Yes, many monitor-side refresh rate meters include LFC multiples in their readings, and yes, many higher refresh rate monitors also start LFC at 60Hz, instead of ~30Hz or ~48Hz.

There’s typically no practical functional or latency difference between 60Hz non-LFCed VRR and 60Hz LFCed to 120Hz VRR, so capping to 65 FPS instead isn’t strictly necessary.

Like4Vote Down 
1 month 23 days ago
ksydew
Member
ksydew

For smoothness sake no difference either? I just do it for perfect frame pacing and also no tearing as well.

Like2Vote Down 
1 month 23 days ago
jorimt
Author
jorimt

Let’s say you’re using a 360Hz physical refresh rate (so something like 120Hz is still a low enough usable multiple):

  1. 60 FPS cap + VRR with LFC that starts at 60 = monitor refreshes 120 times per second, displaying each frame across two refresh cycles.
  2. 60 FPS cap + VRR with LFC that starts at 48 = monitor refresh 60 times per second, displaying each frame across one refresh cycle.

Again, it’s functionally the same; either way, with a 60 FPS cap, you’re getting 60 unique frames per second, with each frame scanning in at the physical refresh rate of the display (~2.8ms per at 360Hz, for instance).

So no, no difference in smoothness, tearing, or latency with otherwise identical settings.

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1 month 23 days ago
ksydew
Member
ksydew

Sorry, one more question because I’m currently about to return a mini LED monitor I bought yesterday because it has severe inverse ghosting and I’ve been too afraid to try an OLED because of VRR flicker. I think I’m going to give the new Samsung budget OLED that recently released a try. Do you have any insight on how to avoid the flickering? I have a really powerful CPU and I’m hoping that if I kept my FPS to 60 or 65 with stable frame rates and frame times I won’t get any flickering.

Like1Vote Down 
1 month 22 days ago
jorimt
Author
jorimt

I’ve explained this before, so I’ll just re-quote one of my previous comments (with some adjustments) below:
 

The amount of OLED VRR flicker is directly tied to frametime performance; the steadier it is, the less the flicker, and visa-versa.

This happens because each variable “Hz/frame” in VRR mode has a slightly different gamma response on OLED in VRR mode (I.E. 60 Hz/FPS gamma can be a tad more washed out vs. 120 Hz/FPS at a physical 240Hz refresh rate, and so on), thus rapid and/or sudden framerate fluctuation makes the gamma differences between them more obvious.

An RTSS limit set to an achievable average framerate will allow the steadiest frametime performance in most cases, but any frametime spikes will still make VRR flicker more evident, especially in darker scenes.

So while you can increase average frametime consistency with an RTSS limit, which will reduce general VRR flicker, there’s no escaping the VRR flicker that occurs on OLED in games with frequent and/or recurring frametime spikes.

Like5Vote Down 
1 month 22 days ago
ksydew
Member
ksydew

Yes to all of that but here is a bit of a tricky thing, and I know you’ve said previously not to count on the monitor OSD to report correctly, but if I cap my fps to 60 the monitor will report it as refreshing at 120hz, but if I cap my fps to 75 it will report it at 75 hz in the OSD. So im a bit confused on if for some reason it’s doubling the refresh rate at 60 for some reason?

Like3Vote Down 
1 month 23 days ago
wpDiscuz

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