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.”



3703 Comments For “G-SYNC 101”

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Ghokury
Member
Ghokury

Would Reflex via RTSS work the same as Reflex enabled in game?
As for FPS, it limits to the same level as normal Reflex.

toby23
Member
toby23

What do you do if using a DX12 game with built in DLSS + Frame Generation e.g. MSFS2020 where Reflex is greyed out and only selectable if using DX11 mode (On/On+Boost)? Do you still set Low Latency Mode to On or to Ultra in NVCP? Thank you

Spooky156
Member
Spooky156

Four questions because I have been reading this article multiple times and still don’t understand.
One: for example, if I’m playing a game and the gpu util is at like 95% and I’m getting fps below my refresh rate of 144hz. I would enable reflex alongside gsync + nvcp vsync, instead of ingame cap for less latency because it already auto caps. Or does reflex only achieve less latency at exactly 99%+? Like basically does 90%-98% still count as gpu bound or only 99%+
Two: If I was playing a cpu bound game like roblox which is dx11 I know you’re not supposed to enable llm because it is for gpu bound but would it hurt just having it on globally?
Three: If I was playing a competitive game and was getting like 80% gpu usage and 35% cpu would turning on reflex help latency or is that not a gpu bound scenario?
Four: on a game like gta 5 (no reflex or ingame limiter): 99%+ gpu usage and 30% cpu usage. Would gsync + nvcp vsync + llm on be better than gsync + nvcp vsync + nvidia max frame rate. which has less latency.
Sorry for all the questions and if they are the same I’m still pretty confused and that is why I’m asking all this in the first place.

taef
Member
taef

so I have 540hz monitor but it’s 500hz bc I’m using windows 10, I’m playing fortnite and for so long I struggled with drop frames, even with low settings and low usage of both cpu and gpu, I’ve tried your method gsync+vsync and capped frames. the game running soo much better. thanks to you. but I’m still experiencing some drop frames but not as much as before, what should I do at this point. and what to cap my frames at?

voicon
Member
voicon

If my screen is 165Hz, and I play Pugb Moblie on Gameloop at only 120 Fps, how do I optimize the latency?
Currently I still have lag when shooting

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