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.”



3707 Comments For “G-SYNC 101”

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Sort by:   newest | oldest | most liked
PootKlopp
Member
PootKlopp

I know that this is a G-sync specific setup guide but it would be interesting to see specific recommendations and drawbacks for those (competitive FPS players) that might be interested in having the absolute lowest input lag.

I would be interested in seeing what FPS you would have to consistently hit over your max refresh rate when running G-sync / V-sync off vs your recommended settings to see improvements in input lag. If that makes sense. What would be the point (2x, 3x, 5x FPS etc.) that you would have to maintain to see an improvement in input lag vs recommended.

Wow, this stuff is hard to describe in words, thanks for all the work you have put in!

p1r473
Member
p1r473

Any idea why Nvidia hasn’t released any of this information themselves? Or implemented any sort of NVCP limiter themselves?
I wonder how many people out there are using G-Sync without frame limiting and not getting the full benefit!
If you ever redo the graphs, a -3 limit would be cool for reference
You are doing a service to the community, keep up the great work, and post a donation link if you have one!

p1r473
Member
p1r473

Hi, I read the part why -3 frame limit is recommended over -2.
But why isn’t -1 at all considered? It looks like -1 has immediate benefits over 0 rate limit.
Is this due to the 1 added frame from RTSS?

iNFAM0US HAV0C
Member
iNFAM0US HAV0C

I’ve got a question to make sure I’ve set this up properly as well.

My Hardware Setup:
– LG 32UD89-W (Functions very similar to the 99-W variant, minus the HDR. Has max refresh of 60Hz).
– EVGA GTX 1070 SC.
– Running through Display Port.

And so if i’m understanding this article correctly, the following is my setup on the software side of things:

NVIDIA Control Panel:
– Manage 3D Settings:
– – Max Frame Rate: 57 FPS
– – Monitor Technology: G-Sync Compatible
– – Vertical Sync: Use the 3D application setting

– Set Up G-Sync:
– – 1. Enable G-Sync, G-Sync Compatible: Checked
– – – Enable for full screen mode: Checked
– – 3. Enable Settings for the selected display model: Checked

Game Settings (Current Modern Warfare for Testing):
– Full-screen: On
– V-Sync: On
– Render and Display Resolution: 2560 x 1440

After testing this method out vs the way I was doing it before which was not setting a Max Frame Rate; I don’t know if my eyes are trained enough to see the difference, but I can’t see much of one. But if this article is true, then my current setup of lower the FPS by -3 from 60 is better in the long run instead of letting it hit it’s usual 60 max, correct?

P.S.: I have no idea if under the “NVIDIA Control Panel” I should be having the “Vertical Sync” be set to “Use the 3D Application setting”, is that correct as well?

pApap124
Member
pApap124

Is there any difference if I have GSYNC with VSYNC off and a -3 fps cap rather having VSYNC ON with the same -3 fps cap?

wpDiscuz