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.”



3696 Comments For “G-SYNC 101”

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Pointi1978
Member
Pointi1978

Hey jorimt,
what is your opinion on the NVidia driver situation at the moment, regarding forcing VSync in the NVidia App in many games using Frame Generation not working correctly at the time? (GPU underutilized despite not hitting the Framerate Cap)
Examples: Half Life 2 RTX Demo, Hogwarts Legacy, Indiana Jones and the Great Circle, Cyberpunk 2077, Alan Wake 2, just to name a few)
Driver Issue? In combination with what? The new hardware flip metering they introduced with 572.16? Reflex not working correctly with the new drivers and the new Frame Gen? Conflicting with image flipping of the OS?

juanma_3
Member
juanma_3

Hi!
I’m new to this and I have a little doubt after seeing the Gsync + vsync guide, in the Nvidia panel, I have to activate the option to “let the 3D application decide” or “use advanced 3D image settings”
Thank you very much for the help

kokblaster32
Member
kokblaster32

If I cap my fps in-game, is there any benefit to using Gsync alongside Vsync? Im asking this, because Gsync sometimes causes flicker in dark scenes, making dark parts of the image to flash gray. Disabling Gsync always solves this, some games are much more sensitive to it than others. I always cap my fps in-game to prevent gpu usage from reaching that 95%-> range.

Jsmooth57
Member
Jsmooth57

Hello jorimt,

I stumbled on the below comment on this thread recently:

https://www.reddit.com/r/nvidia/comments/1ja7drf/is_gsync_vsync_reflexframe_cap_of_3_less_than/

“A frame cap of (max RR – 3) is not universal, it only works for low refresh rate displays, between 60-120Hz.

As refresh rate increases, you need a larger buffer between max refresh rate and target frame rate.

As an example, At 240Hz, the target should be 224 fps.

This is because low-latency framerate limiters are not perfect, and with a 240fps limit on a 240Hz screen, with V-sync on, you’d expect 50% of frame times to “bump into” V-sync and cause increased latency. Lowering the framerate limit to 235 fps will cause this ratio to drop to about 25%, which is better but still quite high. At 224 fps, it’s only around 7%.

You can easily see this for yourself with a performance capture with CapFrameX.

If you are using frame generation though, that changes the equation a little. Sticking with just X2 mode, it’s ultimately lower latency to aim for a higher base framerate, for example, 120->240 is lower latency than 112->224″

Check out Cpt Tombstone’s links – I would love your take on it – should we be capping at more than -3 max refresh rate the higher our monitor’s refresh rate?

eggybread
Member
eggybread

If in a specific game I get a solid FPS. Should I still keep vsync enabled? I use Gsync + Vsync + Ultra low latency if the game doesn’t have the option. I was reading places that vsync can cause input lag, just wanted to double check what is the correct way around this. I have a 165hz monitor, the game I play I get a solid 158 FPS with these settings. Is there any downside to having vsync enabled like this?

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