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.”



3747 Comments For “G-SYNC 101”

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msifanboy
Member
msifanboy

is there any benefit reducing the VRR range lower than 45-48? my Optix MAG251RX can go down to 25hz, but i ran gsync pendulum demo and doesnt seem to be any benefit, and could it introduce more input lag? also is any benefit to make the display “native” in CRU

Pixeldew
Member
Pixeldew

I have an issue relating to gsync (more specifically gsync compatible i guess) modes. I’ve seen people say that there are issues of some sort with enabling gsync for windowed compared to full-screen.

I always have full-screen only enabled in the NVCP for gsync since I usually play in exclusive full-screen, however with the release of elden ring I’ve noticed the game feels smoother using borderless rather than full-screen (I think the full-screen mode changes the monitors fps to 60 rather than just capping the game).
Using borderless however I’m unsure if gysnc is working since I don’t have the windowed option enabled and once again, people online argue that borderless gsync does/doesn’t work with only full-screen gsync enabled.

I would love if someone more technically skilled than me clear the air if there is any downside to enabling full-screen+windowed, and if the “full-screen only option” supports gsync in borderless.

GGGQEP
Member
GGGQEP

Hello. I have bought ASUS PG279QM monitor. I was playing Doom Eternal and I was experimenting with GSYNC NVCP settings and I found some interesting behaviour. Nvidia driver version is 511.79.

1) NVCP Panel GSYNC ON + NVCP VSYNC ON = nvidia performance overlay shows me constant 239 fps rather than 240 fps. Also I can’t feel any input delay of VSYNC that is supposed to be turned on in this scenario…

2) NVCP Panel GSYNC ON + NVCP VSYNC OFF + 240 NVCP fps lock = nvidia performance overlay shows me exactly 240 fps rather than 239 fps.

I wonder if this monitor has newer version of GSYNC module that is capable of autolocking fps within GSYNC range by using GSYNC ON + NVCP VSYNC ON (in game VSYNC OFF).

Does it mean that it automatically locks my fps within GSYNC range if I just use GSYNC ON + VSYNC ON without locking it to 238 fps or it is just a visual bug of nvidia overlay? I mean this monitor is new and maybe it has newer version of GSYNC module that is capable of doing it but I’m not sure.

connor
Member
connor

hey I think my comment got glitched because I don’t see it after approval so I would like to say thanks so much for giving us all of this info as it really helps us understand. I have two questions I would like to ask, 1. does this all apply to “gsync compatible” displays too? if so then does v sync add or help stutter when pairing with g sync? and 2. when I look at the test above, v sync has stutter whereas gsync doesn’t. is it because that test is showing standalone v sync? thank u.

gamererz
Member
gamererz

This article is exceptional and has been a great point of reference for a lot of excellent g-sync discussion. I had a question regarding g-sync’s relationship with the use of reflex.

In my own testing, reflex on maxes out gpu clock just like reflex on + boost. When reflex is not on, gpu clock downscales when gpu usage is low; this never happens with reflex on (whether just on or on + boost). It is my understanding that on + boost means it will also not downclock when in a cpu-bound scenario.

How does this link to the way reflex’s automatic fps limiter works in keeping a monitor within the g-sync range?

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