G-SYNC 101: G-SYNC vs. V-SYNC OFF


Beyond the Limits of the Scanout

It’s already been established that single, tear-free frame delivery is limited by the scanout, and V-SYNC OFF can defeat it by allowing more than one frame scan per scanout. That said, how much of an input lag advantage can be had over G-SYNC, and how high must the framerate be sustained above the refresh rate to diminish tearing artifacts and justify the difference?

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

Quite high. Counting first on-screen reactions, V-SYNC OFF already has a slight input lag advantage (up to a 1/2 frame) over G-SYNC at the same framerate, especially the lower the refresh rate, but it actually takes a considerable increase in framerate above the given refresh rate to widen the gap to significant levels. And while the reductions may look significant in bar chart form, even with framerates in excess of 3x the refresh rate, and when measured at middle screen (crosshair-level) only, V-SYNC OFF actually has a limited advantage over G-SYNC in practice, and most of it is in areas that one could argue, for the average player, are comparatively useless when something such as a viewmodel’s wrist is updated 1-3ms faster with V-SYNC OFF.

This is where the refresh rate/sustained framerate ratio factors in:

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 shown in the above diagrams, the true advantage comes when V-SYNC OFF can allow not just two, but multiple frame scans in a single scanout. Unlike syncing solutions, with V-SYNC OFF, the frametime is not paced to the scanout, and a frame will begin scanning in as soon as it’s rendered, regardless whether the previous frame scan is still in progress. At 144Hz with 1000 FPS, for instance, this means with a sustained frametime of 1ms, the display updates nearly 7 times in a single scanout.

In fact, at 240Hz, first on-screen reactions became so fast at 1000 FPS and 0 FPS, that the inherit delay in my mouse and display became the bottleneck for minimum measurements.

So, for competitive players, V-SYNC OFF still reigns supreme in the input lag realm, especially if sustained framerates can exceed the refresh rate by 5x or more. However, while at higher refresh rates, visible tearing artifacts are all but eliminated at these ratios, it can instead manifest as microstutter, and thus, even at its best, V-SYNC OFF still can’t match the consistency of G-SYNC frame delivery.



687 Comments For “G-SYNC 101”

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v0rken
Member
v0rken

Should I be using this with a 144 Hz monitor even though in the game I’m playing (Valorant) I can hit 300+ FPS? Is GSync + All Settings Above + 144 Hz Monitor with FPS Limited better than FPS Unlimited? Basically 144 Hz @ 141 FPS is better than 144 Hz @ 300 FPS? This with a very high end PC (2080 Ti + 9700K). Thanks for any response and clarification, very much appreciated !

Grisss
Member
Grisss

Hello,

So if I’m correct, I should:
G-Sync ON + V-Sync ON(from NVIDIA panel) + FPS -3 limiter – On all games where I can get above 144fps ( csgo/lol, etc…)
and
G-Sync ON + V-Sync OFF + No FPS limiter – On all games where I can’t reach above 144fps ( for example Singe Player games like The Witcher 3 etc ?)

Is this correct or not?

Thank you

tonga15
Member
tonga15

Mam monitor gsync 27 cali ag271qg.Moje pytanie jest takie , jak ustawić prawidłowo skalowanie pulpitu.Są 4 opcje oraz skaluj na gpu lub monitor.Pomoże mi ktoś ?

neoflo22
Member
neoflo22

Deleted*

neoflo22
Member
neoflo22

I’m playing Red Dead Redemption 2 on 1440P and getting around 53-57 fps. I use a G-sync 144hz monitor. I have 144hz enabled on monitor and 144hz enabled in Red Dead 2 game options. I have Gsync enabled in my Nvidia control. My question is should I enable Vsync and/or set a max frame rate limit.

Generally, the advice is to set 2-3 fps under max (141 cap for a 144hz monitor) but considering my base fps in Red Dead Redemption 2 is 53-57 fps do I need to set that cap, set the cap lower, and/or enable Vsync along with that? Sorry for all the question, I’m just a tad confused after reading all of this.

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