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.

NVIDIA Control Panel Retirement

As of NVIDIA driver version 610.47, the NVIDIA Control Panel has officially reached EOL:

“After 20 years of dedicated service, the classic NVIDIA Control Panel is officially retiring for Game Ready and Studio Drivers. For NVIDIA RTX PRO users, the NVIDIA Control Panel will continue to be supported until we have migrated professional features to the NVIDIA app

Existing installs of the NVIDIA Control Panel will remain on users’ systems, unless they perform a clean installation, and users who still need the NVIDIA Control Panel can continue to download it from the Microsoft Store, but we won’t be adding features, fixes, or other changes.”

While the original NVIDIA Control Panel settings locations will be retained below, the NVIDIA App settings locations are now also included for a more up-to-date reference.

G-SYNC Activation

“Full screen” / “Enable for full screen mode” (exclusive fullscreen-type functionality only) is automatically selected when a supported display is connected to the GPU. If G-SYNC behavior is suspect or non-functioning, tick off, apply, tick on, and apply.

G-SYNC Windowed Mode

“Full screen and windowed” / “Enable for windowed and full screen mode” allows G-SYNC support for legacy windowed and borderless windowed modes. This option was introduced in a 2015 driver update, and by manipulating the DWM (Desktop Windows Manager) framebuffer, allows 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. As such, per-profile application of this mode is optimal vs. global. See Closing FAQ #5 for instructions.

Note: this setting may require a game or system restart after application; “Show indicator” / “G-SYNC Indicator” can be enabled to verify it is working as intended.

G-SYNC Preferred Refresh Rate

“Highest available” is automatically selected when G-SYNC is initially 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-type modes. For games being run in legacy borderless or windowed modes, the desktop always dictates the refresh rate.

  • NVIDIA App
    Settings location

    The NVIDIA App does not expose the legacy “Preferred refresh rate” setting.

    While it is no longer directly accessible in the app, like with the NVIDIA Control Panel, it is still automatically selected when G-SYNC is initially enabled, just internally, and can alternatively be accessed via the NVIDIA Profile Inspector (download here):

    Blur Buster's G-SYNC 101: Control Panel

  • NVIDIA Control Panel
    Settings location (legacy)

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 “Vertical Sync” entry is automatically set to “Use 3D app setting” / “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.”



3847 Comments For “G-SYNC 101”

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VictorPL
Member
VictorPL

Hello!

This is a great guide, and has been very useful to me.

However, I was wondering, how well does it translate to FreeSync and Intel’s VRR implementation?

I was especially curious about the V-Sync details, since its behavior under G-Sync seems very specific to the implementation.

Yezaen
Member
Yezaen

Hey, I am trying to get the most stable framerate in ac shadows, my config is gsync enabled, vsync enabled in Nvidia cp, but I encountered this:

If I set fps cap at Nvidia cp or in-game, the frame pace, the 1% lows are always 10-20 less than the avg and bc of that I notice microstutters.

However, if I use rtss, the frame pace line is completely flat, thus making the game smooth with a absolutely no stutters, it’s like I have the old vsync enabled.

Why exactly is this happening? Why only rtss is able to achieve that and not Nvidia or in-game?

polce24
Member
polce24

Hi there,

Is my VRR working correctly? I’m trying to understand how VRR actually works and whether mine is behaving correctly.

Build/Settings:
9800X3D
RTX 5080
LG 240Hz OLED
G-Sync ON
V-Sync ON in NVCP only
V-Sync OFF in game
Reflex ON when available
VRR enabled on monitor and Windows 11

Last night in Helldivers 2, my FPS was hovering around 160-180. When I check the monitor’s VRR/FPS value in the OSD, it matches the in-game FPS exactly and changes in real time with it. Motion is clear and smooth with really no issues at all.

In ARC Raiders and Overwatch 2, when I use Reflex (which caps FPS at 225), I notice something different. The in-game FPS shows 225 consistently, but the monitor’s VRR/FPS value sometimes hits 240, rarely stays at 225, and often bounces around wildly instead of matching the in-game FPS like it does in Helldivers. I experience a bit of texture judder in both games.

Here is a pic of my FPS capped at 225 at the top-left and my monitor menu showing 240.

How exactly does VRR work at a technical level?

To me, it seems like…

-Below 200 FPS…monitor VRR matches in-game FPS exactly.

-When FPS is capped (Reflex cap or manual cap) OR approaching max monitor HZ…monitor OSD often shows values jumping to 240Hz or not matching the in-game FPS at all.

Is this normal behavior when hitting a cap near the panel’s max refresh?

Could this indicate VRR disengaging at the monitor HZ ceiling?

Just trying to understand whether this is expected behavior or if I need to make some kind of setting adjustment.

Robi
Member
Robi

Hey, Im a huge fan of your work and this as helped me a lot since I build my pc years ago, I appreciate your work a lot.

I have done some testing myself with RTSS Fps Cap with NVIDIA reflex in RTSS settings and found that it has the same latency as the in game frame cap.

Gsync On + Vsync On (NCP)
With an RTX 5090 the gpu load is way bellow 99% at around 45% during testing.

I tested with The First Berserker khazan at 120FPS in game cap which gave a LAT: ~14ms same with RTSS Nvidia Reflex mode. But with RTSS async I got ~25ms

Here is where things get interesting, the mentioned test was done while having Reflex On in the game menu, once I turned it off the RTSS with Nvidia Reflex went to ~25ms so my guess is that if the game has Reflex off RTSS frame cap uses async even though its set to Nvidia Reflex in RTSS settings.

But with Reflex on in game, RTSS frame cap with Nvidia Reflex setting gives same latency as if it was an in game frame cap if this is consistent across other games this could be huge since you could have an in game fps cap equivalent but globally, a set and forget.

Another interesting thing to note, at least in this game Gsync on + Vsync on + Reflex On + Boost does not automatically limit fps to my monitor refresh rate 165hz Reflex in other games limits fps to 157 automatically.

Another small detail, RTSS frame cap reflex seems to take priority over in game frame cap when both are set no matter what frame cap number, RTSS async only takes priority if its lower than in game fps cap.

If you find this interesting I could make a video and show you all my findings 😀

user2422
Member
user2422

When using G-Sync + V-Sync + FPS Limit, should I set Maximum Pre-Rendered Frames to 1 inside the NVIDIA Profile Inspector?

What are you personally using for this setting?

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