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.”



3751 Comments For “G-SYNC 101”

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Agitatio
Member
Agitatio

Hello again jorimt! I noticed that something changed about the Max Frame Rate option in NVCP, although I’m not sure since when. It doesn’t lock to the exact value you set anymore, but instead to a value that equals set value minus some arbitrary offset. In my case when setting it to 240 makes FPS show up as 228-230. With 238 value I had before it frequently showed up as being around 225, which made me think that ULLM was somehow active. Could you maybe investigate that or do you know about some patch notes that had this mentioned?

mario64
Member
mario64

Thank you for this fantastic article. Would these settings also be applicable with a Freesync / adaptive sync monitor?

0OClicKO0
Member
0OClicKO0

I have an interesting question with reflex. Does reflex auto frame cap with Gsync + Vsync have the same, more, or less input lag than the in-game frame limiter, i mean limiting the framerate less than reflex to override the reflex cap and avoid a possibility of more input lag with the reflex limit than the in game frame limiter. I want to see a test with that. You have homework jorimt 😉

0OClicKO0
Member
0OClicKO0

i need help with this. I’m having an interesting situation when i enable G-sync and vsync. When i only use G-sync and cap 4 frames below the refresh rate(144) to 140 without enabling vsync i have the lowest input lag but with tearing in the bottom. when i enable both, the frames automatically caps to 138 without using any fps limiter. I don’t know why it happens, im using the vg259qm 280hz G-sync compatible monitor and idk if the monitor does it, could be because was launch in 2020 and it’s recent i guess. When i disable G-sync and just use Vsync the fps caps at 144 like normal, is when i enable both when the frames caps automatically. But the problem is that with both G-sync and Vsync enabled (i don’t have the tools to test it) I feel more input lag than Vsync off but also less input lag than Vsync on and G-sync off with 144 fps. I saw the test made by jorimt and it shows that G-sync on + vsync off + 142 fps cap shows the same input lag as Gsync on + Vsync on + 12 fps cap. But in my experience in having more input lag as I said before with Gsync on + Vsync on than Gsync on + Vsync off.

Edit: Edit: i found that nvidia reflex is what is capping automatically the framerate to 138 when i have enabled both Gsync and Vsync. With 100hz it caps to 97, with 120 it caps to 116, with 144 it caps to 138, with 240 it caps to 225, and with 280 it caps to 260. But anyways with Gsync on + Vsync on i feel like 1/2 frame input lag higher than Gsync on + Vsync off. I want to know why because in jorimt test it shows the same input lag.

svatt
Member
svatt

Hello, i bought gsync compatible monitor(in nvidia list) and i have one question. I have turned on vsync in almost every game but not in csgo because of input lag. Can it damage gsync somehow? or is it good to not have turned on vsync. I have it turned on in games like ac oddysey, far cry, etc.. but not in fps game.

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