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.”



3172 Comments For “G-SYNC 101”

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Sort by:   newest | oldest | most liked
RagingZ
Member
RagingZ

Have been having a ton of issues with screen tearing, and while reading through the 101 I’m not quite sure I found the answer i was looking for…

New 4090 playing on 4k 144mhz, on a M32u which isn’t claimed to be Gsync compatible but the majority of people say that it is and can confirm the Gsync logo in the top right when enabled. Persistent screen tearing in every game, with a majority of them improving somewhat with vsync however its still clearly there. Have tried lowering the frame limit to both 143 and 142, in addition to using decimals (143.88, etc) but have no improvement. I’m not traditionally going over 144 mhz unless on Warzone or older games but the screen tearing is the same. Have never tried Fast sync because it doesnt really seem like it would offer any benefit, and triple buffer has been turned both on and off, with Vsync both on and off without any improvement. Lowering settings does not improve my screen tearing, which is even occuring with games like League of Legends (which has been tested using the above methods). I’ve replaced cables, updated the firmware to F11 with no improvement. The general average frames im getting among Jedi Survivor (stutter city, tearing), Hogwarts Legacy (tearing, less stuttering), Cyberpunk (screen tearing) seem to be between 60-70 at their lowest, 130s at their highest. Using all updated drivers. Help me out here, I’m pulling my hair out.

port333
Member
port333

With driver 546.33, low latency mode now gives the options off or ultra instead of on. What should we use?

sly
Member
sly

Hi jorimt,

When my CPU and GPU is both good enough for the game. And, with G-sync On, V-sync (NVCP) On.

Any difference on input lag when choosing ‘Nvidia reflex on’, ‘Nvidia reflex on+ boost’ and ‘Nvidia reflex off’?

Sorry for the specific question. Appreciate your inputs.

sly
Member
sly

Thank you so much jorimt,

The article is so useful. Recently I’ve been confused about my gaming setups G-sync, V-sync, and Nvidia Reflex. I would appreciate it if you could answer my questions.

Background:
My display is AW2721D, a 1440p 240hz w/ G-Sync. My fps playing Dota2 will vary from 160-250.

Here are my questions:
1. ‘Vsync on + G sync on + in-game limiting 237’ vs ‘Vsync on + Gsync ON + Nvidia Reflex on& boost’
Which will have the lower input lag? Is Reflex a necessary choice when I’m using Gsync and Vsync?
2. When facing a low fps (160 fps occurs when the average is 240), will turning on V-sync making higher lower in put lag than not turning on V-sync on?

Thanks much for your inputs

Hudson

kamikazegod
Member
kamikazegod

What about V sync option “fast”, should it be used?

wpDiscuz