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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gid1
Member
gid1

Hello, I have a question about in-game frame limiters. Do developers usually account for the recommended ~-3 frames? For example, if a game has an option to limit presets such as 144, if that is selected, would they limit it to ~141 (or whatever arbitrary number) behind the scenes, or is it a full 144? Meaning it is not reliable?

oliverds
Member
oliverds

Hello Jorimt,

i am a bit confused about the combination of G-Sync and V-Sync.

I am running the following system:

Intel 8700K @ 5 GHz / Gigabyte Aorus Extreme 2080ti Waterforce / 32 GB RAM DDR4-3000 / LG 34UC89B with native G-Sync.

I usually do simracing, espeacially with Assetto Corsa, which is a very CPU-intense simulation (only uses one core), so that the cpu can often reach 94% occupancy when having 50-70 cars on the track.

To reduce the cpuz occupancy, i use a framelimit of 70, in some situations the fps can go down to 55, but this does not bother me.

In the NVCP, i set G-Sync on and use the max. aviable refresh-rate of the monitor. Beforce beeing confronted with several videos, i was using G-Sync together with Fastsync activated in the NVCP, but now i think that this combination isn’t really the best.

What is the best combination of a low input-lag and acceptable cpu-occupancy? G-Sync with activated V-Sync and my 70 FPS-cap? This is really confusing.

With best regards and thanks in advance,

Oliver

TheBeker1
Member
TheBeker1

I’m having trouble with micro stutter, present in all games, i followed the guide, and even tried to clean install drivers and windows, but the stutter is still present, even in the NVIDIA Pendulum demo, the stutter happens inconsistenly, but and of course, there’s a framerate fluctuation that happens with it, i have a 1080Ti and a 9600k, 16gb of ram, and a 1tb SSD.

One of my friends has the same problem, and i’ve seen that is not uncommon on forums, can i blame faulty hardware. or is there something more i can try?

gzmm
Member
gzmm

Hey, i have a 144hz gsync compatible monitor, with 48~144hz range.
If i put the monitor at 120hz, the gsync still work? This will make a 60 fps game looks smooth?

andro92
Member
andro92

First of all thank you for your amazing work.

Now if i understand it all correctly, the optimum usage is this:

Nvcp vsync on, gsync on, frame cap -3/141fps (140 for me thanks to my ocd 🙂 i dont wanna bother with additional app rtss. The latest nvcp frame cap should be on par right ? So set and forget situation from nvcp.

Now my confusion comes from ullm. I have a good cpu. 9900k overclocked to fixed 4.9ghz at all times. Im using windows high perf power plan as well. Gpu is 2080s at 1440p. 32 gig 3733mhz cl16 ram, m2 ssd, clean windows 10 pro without bloatware (again thanks to my ocd). Also i have custom water loop so temps are all ok.

If i set ullm on or ultra all times(set & forget) will i see any negative effect ?

Sample1: game runs at 40-80 fps, gpu bound
Sample2: game runs at set fps cap 140, no gpu bound
Sample3: game runs at 60fps internal limit(mortal kombat 11, ds3, sekiro) no gpu bound.
Sample4: no sync, fixed refresh rate, gpu bound vs no gpu bound.
Note: cpu usage is always low, mostly below 30 but i understand system hiccups can happen even with the cleanest systems.

And what is the difference between on/ultra/ingame reflex ?

Effect of nvcp power management mode ? Should i leave it at default or choose maximum performance. Its ok if it consumes more power.

I’m fan of set&forget type of usage and i dont care if ullm ultra adds another fps limit below my fps limit for some specific game. But i dont want extra input lag or some bug.

My second question:

I was competitive Overwatch player, now i play Mortal Kombat 11 competitively. Motion blur, backlight strobing etc not as important in this but input lag is important. Even 1 frame matters in this game to take your turn. This game designed around 60 fps and it does not strain my gpu however it fluctates between 58-60. What settings are best for this specific game ? Can ullm on or ultra add more input lag if i set&forget ?

And the last topic sorry for wall of text:

Now gsync monitors are 30-144, gsync compatibles are 48-144. My question is how seamless is this this “lfc” or hz doubling/tripling. If my game runs between 40-60 fps is it better to just disable gsync for more fluid experience. What happens at the exact moment when the lfc kicks in ? What is the difference between adaptive sync and gsync module in this topic ?

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