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.”



3032 Comments For “G-SYNC 101”

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ThatBuild
Member
ThatBuild

What would have less input lag/better response on a 165 hz monitor with gsync enabled.

Capping at 144 fps with Vsync “off” or capping at 160 fps with Vsync “on”?

mayc
Member
mayc

One question and sorry for my bad English. My monitor is 120hz and most games do not give me 120fps stable, usually go above 60 (60-80-95-65-…) but there are many peaks. Although I don’t have tearing with the gsync, if I notice sometimes some stuttering with those peaks of fps dancing. I have done some test to force the monitor to 60hz and play at 60fps and I get the feeling that the sensation is more stable, even the scrolls feel softer. Is this technically possible and recommended in these cases or is it pure placebo?

thanks

DjMeleeForm
Member
DjMeleeForm

I have a question about the G-Sync range. I have a 240Hz monitor and have been using the optimal settings stated by this site (G-Sync + V-Sync On (Nvidia control panel), 237 FPS limit), but in certain games there is only a preset number of FPS limiting options (60, 120 and 144hz for example). Is a framerate of 144fps still within the G-Sync range of a 240Hz Monitor or am I forced to use a framerate limiter to get the sweet spot of G-sync with (almost) no additional input latency and no tearing?

Khysarth
Member
Khysarth

Would this be optimal for 240hz monitors also?

WolfStar
Member
WolfStar

Since g-sync allows the monitor and gpu to talk to each other, wouldn’t it be much easier for the gpu to limit its own maximum frame rate output based on the monitor?

To my understanding, once past the g-sync range (ie, your monitors refresh rate) it really just becomes double buffer v-sync and adds a ton of input lag. To combat this you need to then limit the framerate output with an fps cap. If you’re lucky, the game will have one available that limits it at the engine level, great. However if it doesn’t include one you’re stuck with tearing, v-sync lag, or no tearing but still some form of input lag from external fps cap programs. Instead of having to deal with this crap and in an effort to make things WAY more user friendly, wouldn’t it be a lot easier to just limit the gpu frame production internally when gsync is enabled? I’m no gpu engineer and idk if you could even accomplish this, but through either restricting how much the gpu is working, or just limiting what the gpu outputs (though this is basically what vsync does, it would just be internal limiter, so Idk if that would add input lag or not) it at least seems possible.

Btw highly appreciate that you’re still active on replying to people in the comments given the age of this post, though I can tell you’re getting annoyed with repeat questions and the fact this “comment section” is just people asking you stuff. Idk if you can even answer this, but it’s just something I thought of while reading the article. Great read btw and awesome quality of testing and explanation.

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