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.”



1948 Comments For “G-SYNC 101”

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majkool
Member
majkool

Hello @jorimt,
Great article! Have a questions (game CSGO low settings, 144Hz monitor, my fps mostly reach or exceed refresh rate):

    1. In terms of input lag it’s better to use VSYNC (double buffered) in-game because GSYNC is native double buffered or better use it in NVCP?

    2. When using G+VSYNC in NVCP and fps_max 140 I have often fps spikes above it but when I use LLM(Ultra) it’s really stable and there is no spikes above 138fps. Because of that there could be tearing, stuttering or more input lag?

    3. What is best for input lag – G+VSYNC OFF + fps_max 999 or G+VSYNC+fps_max 140?
    Thanks in advance for answer.

Greets!

Vel0X
Member
Vel0X

I have one question and I hope it has not been asked so far. I get that G sync generally is best with the settings you suggest us here.
When I go for the SIM value in OW I get better input lag with your settings, nvcp v sync off, reflex on, uncapped (400) fps than with your suggested settings.

Does that SIM value matter?

Because the picture looks better with your settings but SIM value is like 1ms worse.

pineapplefirestorm
Member
pineapplefirestorm

Hello, love this guide a ton! I have an issue with G-sync I hope you might know what to do with since you’re the G-sync guru around here.

So I play a game called MapleStory, & the best resolution it can really run at is 1366×768 unfortunately. No way around it. It does run at 165Hz though. (There’s a beta 1080p option but it’s bad & as I later describe, the issue is more of a resolution change issue with G-sync. I tried 1080p and saw no difference.)

I also tried other fullscreen games, and the issue I later describe also applies to them when running at non-native desktop resolution – so it is NOT a MapleStory-specific issue to be clear.

I use the Dell S2721DGF with a RTX 3080, single monitor at 2560×1440, DP 1.4 at 165Hz.

As you can figure, 1366×768 is pitifully small to look at on a 1440p screen, so I use fullscreen. And with that, I alt+tab a ton.

And here’s the issue: ONLY with G-sync enabled – whether it is fullscreen+windowed or just fullscreen G-sync – there is a 3-5 second delay when alt+tabbing, likely caused by the resolution change.

To reiterate: it ONLY happens with G-sync enabled. If I simply just disable G-sync, it immediately begins to alt+tab instantly with zero delay.

I have the desktop scaling set to GPU & override, and have restarted multiple times, and used DDU to clean install the latest NVIDIA drivers. HDR is disabled in Windows and at the monitor level.

Any idea on this? Is this a normal/buggy/monitor issue with G-sync? Obviously I’d prefer to play with G-sync enabled, but the 3-5 second alt+tabbing drives me nuts.

Thank you.

Zehdah
Member
Zehdah

Hey Jorimt. Do these settings apply for a monitor using adaptive sync if I have a Nvidia GPU? So can I copy the recommended settings as if I have Gsync? Heard it works the same as Gsync but thought I’d ask to be sure.

blaskovic
Member
blaskovic

Hi jorimt. I have a question for you. Sometime in older games (2011 – 2013) I have a drop frame from 144 to 140 or 144 to 135 and I notice this microstutter with G-sync but in other games if I have this drops (for example in Dirty Rally) I don’t see anything. My question is this: Why in some case (games) G-Sync seems works but in other circumstances (games) i see this microstutter? G-Sync shouldn’t avoid Microstutter? Thank you

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