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.”



3062 Comments For “G-SYNC 101”

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elexi
Member
elexi

Can I ask a few more questions?
1) In 2022, is it already safe to enable the gsync option for fullscreen and windowed mode or i can mess performance?
2) Some games like Keshi or Unity game (dusk) don’t have full screen mode or excl fullscreen, only borderless fullscreen windows, in which vsync doesn’t work. But using gsync for fullscreen and windowed mode somehow nvcp vsync starts working in this games. Is it normal to use such a case for gsync + vsync or is it better to use game vsync? Or Vsync work diffent in this case?
3) Windows 11 has an option to optimize game performance for windowed mode. Does it work fine with nvcp vsync+gsync?

MissEvelyn
Member
MissEvelyn

If I use gsync+frame cap I can see lots of tearing near the bottom of the screen (just like in the posted overwatch video) which is explained in this article as “frame time variances” in the upper range where basically framerate caps are not perfect and sometimes you get frames coming at higher than the monitor’s refresh rate. Page 7 says, “While it’s common knowledge that limiting the FPS below the refresh rate with V-SYNC prevents the over-queuing of frames, and thus majority of added input latency …”, however, I see so much tearing with just an fps cap, and often very high max FPS numbers according to rtss, I wonder if my system may overshoot the fps cap for multiple consecutive frames, in these cases could I be hitting the 2-6 extra frames of input latency caused by vsync when using gsync+vsync+fps cap?

Page 6 says, “However, the delivery of a single, complete frame with G-SYNC + V-SYNC is actually the lowest possible, or neutral speed”, and the FAQ says, “And since G-SYNC + V-SYNC “On” only holds onto the affected frames for whatever time it takes the previous frame to complete its display, virtually no input lag is added; the only input lag advantage G-SYNC + V-SYNC “Off” has over G-SYNC + V-SYNC “On” is literally the tearing seen, nothing more.”, but does this assume only single instances of “affected frames” will occur in a row?

port333
Member
port333

Thank you for this valuable information. I recently got a new build and was wondering what specific settings you would recommend? I have a 4090 with a m32u. Currently in nvcp, I have v sync on, g sync on, LLM ultra and frame limit to 141, but are these settings optimal with this monitor?

akgforgsync
Member
akgforgsync

Hi Jorimt,
I have 144 hz 4k monitor. I cant run pubg always 144hz so is it good to go pc settings and choose 120hz then cap it 117 hz from in the game. (By the way i know i have to go nvidia settings and open gsync / turn on v-sync.) then i will go and cap 117 hz from in the game. Because i think 116 will be more stabil than capping 141. U know PUBG is a broken game. So its hard to take 141 fps stabil. Thank you.

four4one1two3
Member
four4one1two3

I created an account just to say thank you for the extensive research and this very informative article of yours! It might just be a Placebo, but i def feel like my games feel better now that i followed the guide, again, thank you!

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