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.”



3052 Comments For “G-SYNC 101”

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Neutra
Member
Neutra

Very nice guide, could you clarfiy this for me?:

Setup:

GSYNC-ON + V-SYNC ON (140 fps cap)
Borderless Window mode
main display: 48-144hz with Freesync Premium (LFC)
secondary display: 60hz without G-SYNC/Freesync

Scenario:

48-140 FPS –> G-SYNC active without LFC
24-47 FPS –> G-SYNC still active because of LFC (doubling). V-SYNC still off
23 FPS –> G-SYNC not active because LFC max doubling range isn’t sufficient anymore to reach the 48hz G-SYNC threshold? V-SYNC active? Because of borderless window mode additionally + 1 frame delay?

Thanks =)

cni.nou
Member
cni.nou

Hi,

Thanks for an awesome and detailed guide. I see that this article was published back in 2017 and I am not sure then you have revisited it last time. Would be nice, if you can but it somewhere!

Anyways, I wanted to verify something. I recently got my first monitor with G-SYNC module (Asus PG279QM, 240hz). Before locking down FPS and enabling V-Sync in Nvidia panel I just decided to go with default settings and see what is going to happen.

So far I see no issues, no tearing or drops in games. Is it really required to limit FPS to 237 and enable V-Sync in Nvidia control panel?

Thanks and sorry for the stupid question 🙂

finaltidus
Member
finaltidus

Hi Jorimt. 🙂

Decided to finally register an account to pose a question to you if you ever read this due to having some technical dilemma regarding input lag and G-Sync compatible settings which I am currently having. I have been following the updates made to this article since 2018 and have been a fan of your valuable work for the community. So if you can reply to my problem I will really appreciate it so much! 🙂

Long story short: I just bought a EVGA RTX 3060 and have set up the exact settings in NVCP as per your recommended. My monitor is a rather unknown monitor which is a Prism X315 Pro based in Singapore. This is a VA panel at 1440p at 144hz with freesync.

G Sync Compatible: On
Vertical Sync: On
LLM: Ultra

Now the problem starts because I started experiencing Freesync brightness flickering. More details as below when I googled:
https://www.displayninja.com/what-is-freesync-brightness-flickering/
https://www.reddit.com/r/nvidia/comments/ap6i5l/one_big_difference_in_nvidias_adaptive_sync/

So I used CRU utility to adjust the VRR range of my monitor from 48-144hz to 90-144hz as per the recommendations to reduce the very annoying brightness flickering as most of my games vary from 60-90fps. The problem now is that most of the time the G sync does not activate during gaming as my fps does not hit that range. And vertical sync(*correct me if I am wrong*) will make my input lag worse.

So for my situation, what do you recommend that I do to my settings? I am looking for the lowest input lag while minimising the brightness flickering problem!

THANKS AGAIN IN ADVANCED IF YOU SEE MY HUMBLE POST! 🙂

The Mike
Member
The Mike

Hi, I have a question regarding g sync and input lag.

I have turned on g sync in my nvcp, set fps limiter to a few fps under my monitors fps limit, and turned v sync on.

I notice input lag like mouse smoothing when playing, which drives me nuts as it affects my aim.

When I turn v sync off I get no screen tearing at all, and I have no mouse smoothing.

However, my GPU runs like an insane and really spins loud, making me thinking that this might not be the best approach, as I really fear it could ruin my GPU with the high coil whine.

What is an alternative to capping my GPUs workload? The fps cap doesnt seem to make my GPU work less, and while my GPU turns silent in an instant when turning v sync on, I dont see it as a good solution as I get input lag, or smoothing or whatever to call it.

LidlessEye
Member
LidlessEye

Hi, I have an issue where I don’t know if my problem is screen tearing or any nvidia setting. You can see it in lines or straight things when moving the mouse. This happens in all games. I have a Asus tuf VG24VQ 144hz monitor. https://youtu.be/TX6aq9aCaEY You can see it clearly in Doom or GTA. Is it really screen tearing my problem?

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