G-SYNC 101: Control Panel


G-SYNC Module

The G-SYNC module is a small chip that replaces the display’s standard internal scaler, and contains enough onboard memory to hold and process a single frame at a time.

The module exploits the vertical blanking interval (the span between the previous and next frame scan) to manipulate the display’s internal timings; performing G2G (gray to gray) overdrive calculations to prevent ghosting, and synchronizing the display’s refresh rate to the GPU’s render rate to eliminate tearing, along with the delayed frame delivery and adjoining stutter caused by traditional syncing methods.

G-SYNC Demo

The below Blur Busters Test UFO motion test pattern uses motion interpolation techniques to simulate the seamless framerate transitions G-SYNC provides within the refresh rate, when directly compared to standalone V-SYNC.

G-SYNC Activation

“Enable for full screen mode” (exclusive fullscreen functionality only) will automatically engage when a supported display is connected to the GPU. If G-SYNC behavior is suspect or non-functioning, untick the “Enable G-SYNC, G-SYNC Compatible” box, apply, re-tick, and apply.

Blur Buster's G-SYNC 101: Control Panel

G-SYNC Windowed Mode

“Enable for windowed and full screen mode” allows G-SYNC support for windowed and borderless windowed mode. This option was introduced in a 2015 driver update, and by manipulating the DWM (Desktop Windows Manager) framebuffer, enables G-SYNC’s VRR (variable refresh rate) to synchronize to the focused window’s render rate; unfocused windows remain at the desktop’s fixed refresh rate until focused on.

G-SYNC only functions on one window at a time, and thus any unfocused window that contains moving content will appear to stutter or slow down, a reason why a variety of non-gaming applications (popular web browsers among them) include predefined Nvidia profiles that disable G-SYNC support.

Note: this setting may require a game or system restart after application; the “G-SYNC Indicator” (Nvidia Control Panel > Display > G-SYNC Indicator) can be enabled to verify it is working as intended.

G-SYNC Preferred Refresh Rate

“Highest available” automatically engages when G-SYNC is enabled, and overrides the in-game refresh rate selector (if present), defaulting to the highest supported refresh rate of the display. This is useful for games that don’t include a selector, and ensures the display’s native refresh rate is utilized.

“Application-controlled” adheres to the desktop’s current refresh rate, or defers control to games that contain a refresh rate selector.

Note: this setting only applies to games being run in exclusive fullscreen mode. For games being run in borderless or windowed mode, the desktop dictates the refresh rate.

G-SYNC & V-SYNC

G-SYNC (GPU Synchronization) works on the same principle as double buffer V-SYNC; buffer A begins to render frame A, and upon completion, scans it to the display. Meanwhile, as buffer A finishes scanning its first frame, buffer B begins to render frame B, and upon completion, scans it to the display, repeat.

The primary difference between G-SYNC and V-SYNC is the method in which rendered frames are synchronized. With V-SYNC, the GPU’s render rate is synchronized to the fixed refresh rate of the display. With G-SYNC, the display’s VRR (variable refresh rate) is synchronized to the GPU’s render rate.

Upon its release, G-SYNC’s ability to fall back on fixed refresh rate V-SYNC behavior when exceeding the maximum refresh rate of the display was built-in and non-optional. A 2015 driver update later exposed the option.

This update led to recurring confusion, creating a misconception that G-SYNC and V-SYNC are entirely separate options. However, with G-SYNC enabled, the “Vertical sync” option in the control panel no longer acts as V-SYNC, and actually dictates whether, one, the G-SYNC module compensates for frametime variances output by the system (which prevents tearing at all times. G-SYNC + V-SYNC “Off” disables this behavior; see G-SYNC 101: Range), and two, whether G-SYNC falls back on fixed refresh rate V-SYNC behavior; if V-SYNC is “On,” G-SYNC will revert to V-SYNC behavior above its range, if V-SYNC is “Off,” G-SYNC will disable above its range, and tearing will begin display wide.

Within its range, G-SYNC is the only syncing method active, no matter the V-SYNC “On” or “Off” setting.

Currently, when G-SYNC is enabled, the control panel’s “Vertical sync” entry is automatically engaged to “Use the 3D application setting,” which defers V-SYNC fallback behavior and frametime compensation control to the in-game V-SYNC option. This can be manually overridden by changing the “Vertical sync” entry in the control panel to “Off,” “On,” or “Fast.”



3032 Comments For “G-SYNC 101”

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CaporalFootdem
Member
CaporalFootdem

Hello I am French I apologize in advance for the question I will ask you. It’s a redundant question, but I’m going to ask you anyway.
I have an AOC24G1 144Hz freesync compatible display, which is not in the NVIDIA list but is still G-SYNC compatible.
In some games I am well above 144hz, so I am in G-SYNC + V-SYNC OFF and fps limit to 141Hz.
On other games I am below 144hz, for example 100 FPS, 120FPS, can I stay like that or do I have to make sure that 120-3FPS = 117 or enable V-SYNC in addition to G-SYNC and LIMIT FPS

THANK YOU SO MUCH

Lv69Magikarp
Member
Lv69Magikarp

Hello, I would like to ask if with a G-Sync compatible monitor you have to cap the fps lower than 141.

GiantPizza
Member
GiantPizza

Hello, I really like this site and you seem to be the most knowledgeable person in this subject. I’m using a gsync compatible monitor (lg 27gl850) with an nvidia Gpu (RTX 2070 Super). I Have tried gsync + FPS capped at 135 using rtss with v-sync turned on and also off in the nvidia control panel. From the information i could gather so far it seems to me that v-sync on in this case is suppose to provide a smother tear free experience without added input delay over v-sync off, yet it feels to me that v-sync off has less input lag. Could the smoother image with vertical sync turned on cause more perceived delay when in fact it is about the same, or there may be something else going on here?

Robert Ehrling
Member
Robert Ehrling

Hello, I use a Nvidia Adaptive sync on a SAMSUNG Freesync2 monitor, I have enabled G sync in the control panel and followed your recommendation about using Nvidia Inspector to control the behavior. I set use on full screen and then got a game profile (iRacing) for allowing G sync running in windowed mode.

My question is about that an overlay added (some relative and standings) to iRacing is taking focus and breaks the G sync and is there any settings that I can do to prevent this. The little banner that says “using G sync” disappears when the overlay is added and there is clearly a differens to in the smoothness of frames.

Robert Ehrling
Member
Robert Ehrling

Your suggestion to a solution did not work but thanks for your answer, much appreciated!

Spector
Member
Spector

Hello, i have a couple of questions regarding the subject discussed in the previous thread.
I have 240hz gsync compatible display (alienware 24inch to be more precise, in case that matters).
Is it worth doing this to get lower input lag in games that i might not hit the 235(237 as set in your tutorial) fps limit? For example if i’m playing game X and i usually get 150-160fps instead of 235 fps, will setting the fps limit to 235 add input lag to the game compared to setting it to 140-141?
One more question would be (and it might be a little off topic), but is me locking my frames to 141 going to get me better 1% frames then locking my frames to 235(or 237)? I am asking that since i hate micro stutters.
And if i usually get an average frames of 200ish and the 1% are in the 120 area, will i be benefiting from capping at 237 or 141 (the question only makes sense if there’s a reason to cap my frames much lower than my refresh rate in the case i have way less frames than what my “refresh rate would be capable of”.).
Thank you in advance for taking your time to answer my question.

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