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.”



2981 Comments For “G-SYNC 101”

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pervail
Member
pervail

Hello there, I’m in a weird situation, in my case I am GPU Bound in certain games, I am playing on a 240hz monitor but cannot always reach a consistent 240 fps. However, I can reach a stable 144-165 fps. Ideally, I’d like to have the most consistent experience as I mainly play competitive fps games.
So, in my case should I be enabling GSYNC + VSYNC + 144/165 fps cap in the NVCP? When I enable an in-game cap of 144 fps the fps will still often go above 144 fps and sometimes read 145-146 so I’m not sure if should be using the in-game fps cap.

yamaci1775
Member
yamaci1775

I have a weird question. I see a mention where higher prerender queues being helpful for lowend CPUs catching up with GPU / having smoother performance.
If someone has such a lowend CPU in 2024, is there a way to manipulate the engine to use more prerender buffers with dx12 games?
As in the CPU bottleneck situation, GPU gets underutilized and queues almost get close to 0. I feel like CPU gets hit more and I get more stutters and whatnot. If I can get GPU to consistently %99 I get stable and good frametimes with lower framerate avg (no problem with this one).

I’m asking this as it prevents me getting a decent Gsync mileage out of CPU bottlenecked situations. Up until some point I was able to circumvent the issue on my 3070 by pushing enormously high resolutions that led to healthy GPU usage increase. Nowadays VRAM became a big limitation it is not rare I find myself in situations where GPU hovers around %60-80 with CPU left with stutters due to no queues.

I know CPU upgrade is the real reason but I still wonder if it is possible to somehow trick the engine to use more prerender frames in CPU bottlenecked scenarios to help my aging CPU a bit.

xpnkz
Member
xpnkz

Hey!

Always loved your guide, been using it for years, thanks for your work.

I have a question, if you have any knowledge about this kind of setup. I have a laptop with a AMD iGPU and Nvidia dGPU, supports FreeSync on the built in panel connected to the iGPU (no MUX switch), should I enable v-sync in NVCP or leave it to the iGPU?

Thanks!

zzmadd
Member
zzmadd

Hi there,

thanks a lot for this amazing 101.
I’m trying to internalize.

I play Sim Racing titles like iRacing, Assetto Corsa Competizione etc etc.
I have triple screen to show the cockpit and drive..
I can use those apps both in Borderless mode spanning the resolution accross the 3 monitors using a third party app or using Nvidia Surround and then setting the apps in Full Screen.
Is there a preferred method? The Avg Fps I measured in different scenarios are the same.
Sim Racing is hugely input lag sensitive, the goal is to try and optimise as much as possible the system.

Thanks.

Ryuga
Member
Ryuga

Hello my savior . I have been using your config for quite sometime now . However I make a single mistake . I was using G sync + v sync + max framerate limiter in NVCP -3 + Ultra low latency , which is wrong because in your post , you said if I have framerate limiter on , I should use Low latency On mode only ( no ultra ) . So I switch to On but then I get massive FPS drop in game . So then I switch to the other method . No frame cap + Ultra low latency and the frame drop got fixed tremendously . it still drop occasionally but not as frequent and not a masslve FPS drop like 50 FPS like before .

Another thing I want to ask you for your opinion . Yesterday I watch a video with proof of testing showing that G sync + v sync + Ultra low Latency got last place in every latency test . He said it might be that the Nvidia new driver break Low Latency mode somehow , So the most reliable way to set up now is G sync + V sync + Frame cap in RTSS or NVCP or in game if Possible with Low latency mode not on Ultra or Reflex in game . Can you Shed some light on this

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