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


Identical or Fraternal?

As described in G-SYNC 101: Range, G-SYNC doesn’t actually become double buffer V-SYNC above its range (nor does V-SYNC take over), but instead, G-SYNC mimics V-SYNC behavior when it can no longer adjust the refresh rate to the framerate. So, when G-SYNC hits or exceeds its ceiling, how close is it to behaving like standalone V-SYNC?

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

Pretty close. However, the G-SYNC numbers do show a reduction, mainly in the minimum and averages across refresh rates. Why? It boils down to how G-SYNC and V-SYNC behavior differ whenever the framerate falls (even for a moment) below the maximum refresh rate. With double buffer V-SYNC, a fixed frame delivery window is missed and the framerate is locked to half the refresh rate by a repeated frame, maintaining extra latency, whereas G-SYNC adjusts the refresh rate to the framerate in the same instance, eliminating latency.

As for “triple buffer” V-SYNC, while the subject won’t be delved into here due to the fact that G-SYNC is based on a double buffer, the name actually encompasses two entirely separate methods; the first should be considered “alt” triple buffer V-SYNC, and is the method featured in the majority of modern games. Unlike double buffer V-SYNC, it prevents the lock to half the refresh rate when the framerate falls below it, but in turn, adds 1 frame of delay over double buffer V-SYNC when the framerate exceeds the refresh rate; if double buffer adds 2-6 frames of delay, for instance, this method would add 3-7 frames.

“True” triple buffer V-SYNC, like “alt,” prevents the lock to half the refresh rate, but unlike “alt,” can actually reduce V-SYNC latency when the framerate exceeds the refresh rate. This “true” method is rarely used, and its availability, in part, can depend on the game engine’s API (OpenGL, DirectX, etc).

A form of this “true” method is implemented by the DWM (Desktop Window Manager) for borderless and windowed mode, and by Fast Sync, both of which will be explained in more detail further on.

Suffice to say, even at its worst, G-SYNC beats V-SYNC.



2630 Comments For “G-SYNC 101”

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alonzo_waters
Member
alonzo_waters

Hi, Amazing post I must say! I am having some trouble. I have a 1440p 240hz Gsync ultimate monitor with a 3080 & 13th gen cpu. I am trying to set up apex to run smooth so I followed this guide as in Gsync on + vsync nvcp on with vsync off in game while reflex is on & fps cap with RTSS. My game stutters no matter what with this set up when dropping out of ship regardless of my stable fps. It’s specifically when I look around. When I turn reflex off in drop ship, I can look around without any problems, very smooth.

Once I’m on the ground and playing with these settings, it continues to look very choppy when I look around. It happens when I move my mouse in a circle motion (my fps graph is stable while this happens). I also noticed when I put the command +fps_max 0 the game seems to run a little more smooth but when I delete that command, the game becomes extremely choppy while looking around.

I’m just wondering if I am doing anything wrong on my end as far as my setup? My temps are fine, background apps are not taking many resources at all & I’ve tried many optimizations with NVCP. Pretty desperate at this point as I invested good money into this setup. Thanks you advance! I really appreciate it!

NookFPS
Member
NookFPS

Yooo

Alonzo. I had the same issue and i was going crazy. I always had micro stutters and i didnt know where it was coming from. So for me its running now like this:

NVCP Vsync ON
RTSS Framerate 3 Frames under your Screen refresh rate.

Thats it. For me it was the Framerate limiter. The ingame Apex caused microstutters and the Nvidia Limiter also.

Take the first Option on this link but only with RTSS

https://blurbusters.com/gsync/gsync101-input-lag-tests-and-settings/14/

Kincior
Member
Kincior

What do you think I should run in cs go?

180 Hz with G-Sync + Vsync (NVCP) capped at 177/8 fps
or
165 Hz No Gsync, no Vsync, and uncapped fps?

On one hand I have higher refresh rate but on the other; lower latency.

billy
Member
billy

I play destiny 2 on a 240 hz monitor. I have gsync compatible monitor with in game reflex on and v sync on globally in control panel. But I still get hitches and stutters from time to time. Am I doing something wrong? My cpu is 12900k and i have 32 gb ram 3600

majkool
Member
majkool

@jorimt that’s the best article about that on the internet!

I’m right that for dynamic fps game like CS the best settings are:
G-SYNC on + VSYNC on (NVCP) + LLM on (NVCP) and fps_max 276 because of 280Hz monitor refresh rate?

Regarding input lag it seems exact the same like V-SYNC off + fps_max 276 but what is better when my fps drops below 200 fps which settings are better in input lag?

Igor
Member
Igor

Hello! I apologize for my English, I write through Google translator.
My computer configuration:
CPU: i7-8700K
Motherboard: Gigabyte Z370 AORUS Gaming K3
RAM: Kingston 32GB (2x16GB) 3000 MHz HyperX Predator
SSD: SAMSUNG 850 Pro 256GB 2.5″ SATA
Video card: MSI PCI-Ex GeForce RTX 2080 Super Gaming X Trio
Monitor: ASUS VG258Q 24.5″ 144 Hz 1920Ρ…1080 (Free Sync, supported in nVidia control panel)
Everything is clearly written in your article, but I have two questions:
1. If I set the FPS limit in the nVidia control panel to 72fps, do I need to enable vsync?
2. Some games do not disable FPS capping. For example, like in Nioh 2: minimum: 30 fps, maximum: 120 fps, what would you recommend: should I set an FPS limit? Should you enable vertical sync?
I don’t know if my questions are clear…

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