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.”



3068 Comments For “G-SYNC 101”

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swollenplums
Member
swollenplums

Hi,

Thank you for the guide once again – I’ve been using and sharing this site for years.

I’m currently non-GPU and non-CPU bound with a 165hz monitor. When I use Reflex + Boost in COD Warzone I am getting a FPS cap at 158 (as expected as this is equivalent of setting Low Latency “Ultra” in NVCP).

Is there any advantage/disadvantage of keeping:
Reflex + Boost ON
vs.
Low Latency “On” + Power Management Prefer Maximum Performance + FPS Cap @ 162

(Both with G-Sync “On” and V-Sync “On”)

I know It’s a comical 4 FPS difference, but is there anything else valuable I can get using Reflex instead of Low Latency “On” in a non-GPU bound scenario?

Bonus questions if you have time:
If I’m never GPU-bound (luckily the case with a 3080 so far…) do I ever need Low Latency mode “On” if I’m always capping below refresh rate?
Would you ever recommend going above the refresh rate of the monitor + disabling sync technology + higher FPS cap?

Thanks again for your time!

Red Rooster
Member
Red Rooster

What happens if you have both an in-game framerate limiter *and* the NVCP Max Frame Rate enabled at the same time? Does one subordinate itself to the other, or do they both fight over each other, or is there no effect, etc.?

Mark Rejhon
Admin

The lower of the two would activate. However, in-game caps is typically lower latency than external frame rate caps. So if you use two caps for any reason, set a lower in-game cap than an external cap.

LGLGLTM
Member
LGLGLTM

Hi,

First, thank you for this quality guide.

I have a G-Sync compatible monitor 165 Hz and when I enable G-sync and V-sync in the NVCP, my FPS are locked at 158. i understand that it’s locked because of V-sync but why at 158? Shouldn’t it be locked at 165 fps?
I’ve seen in multiple places that w/ 165 Hz monitor, you should lock ingame (or RTSS if not available) at 160 fps but in my case, it makes no sense since it’s already at 158. Should I lock it even lower like 155 to avoid any input lag that could arise from v-sync? If that’s even possible with this setup.

Thanks.

BlackStorm82
Member
BlackStorm82

240Hz / GSYNC ON / 60FPS
240HZ / GSYNC OFF / 60FPS

Which is better in response time? Which one is better for blur?
G-Sync’s variable refresh rate function Does the screen response speed also affect it?

swaz
Member
swaz

Hi,
NVIDIA recently introduced a new “Max Frame Rate” setting in its Control Panel.
So I’m wondering if that uses the same FPS limiter tested via “Nvidia Inspector” on page 11.
If that’s not the case, when an in-game framerate limiter isn’t available, should I use RTSS or this new setting?
Thanks in advance.

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