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.”



1304 Comments For “G-SYNC 101”

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Jackyboy90
Member
Jackyboy90

For ryzen 3700x which power plan is recommended? Still windows high performance? Or amd high performance?

olui
Member
olui

I have a question. When G-sync is on and refresh rate drops, does the scan time also increase?
So if a 144hz monitor drops to 70hz with G-sync, will the scan time increase from 6.9ms to 14.2ms or will the scan time still be 6.9ms and the monitor won’t scan until the new frame arrives?

EDIT: Never mind, found the answer at https://blurbusters.com/understanding-display-scanout-lag-with-high-speed-video/

“Variable refresh rate (VRR) actually varies the size of the vertical blanking interval (the pause between refresh cycles) in order to temporally space-apart refresh cycles.

The top-to-bottom raster scan stays at a fixed velocity, however the intervals between refreshes can vary instead of being a fixed interval. Here is the scan diagram of 100fps at 144Hz:”

“Another huge benefit of variable refresh rate is very low scan-out lag. A 240Hz G-SYNC monitor can display a 30Hz refresh cycle in 1/240sec, refreshed near real-time off the video cable. This is a “Quick Frame Transport” (QFT) behavior of VRR.”

Solarity21
Member
Solarity21

Hey Jorimt, thank you so much for this guide, I’ve been reading and trying so many things with my new monitor, to the point where I’m not even getting to play any games anymore, so I decided to come here for you to set me straight.

I bought an Asus VG27AQ to play WoW mainly and some other games on the side. The first thing I noticed with Gsync enabled is that I’m getting flashes on loading screens and whenever I get an fps spike while playing. No matter what I did, it looks like it’s impossible to get rid of it unless I disable Gsync. I’m getting a new DP cable (Accell DP to DP 1.2 – VESA-Certified DisplayPort 1.2) which is 1 meter long and that’s pretty much my last option. Perhaps you got some other suggestions about this problem which I haven’t tried yet.

Regardless of flashing, I’m sure I’ll get used to it eventually anyway. My main question however, is about what hz would you suggest me running the monitor at. At the moment I have it Overclocked to 165hz and in the game I’m using fps limiter at 162. Now on Nvidia website, it says Variable Refresh Rate Range for my monitor is 48-144Hz, would that make any impact on how Gsync performs?

Also wanted to ask if Low latency mode as On, or Ultra would make any difference for WoW? I see people in comments saying they have it on and you would always respond that that’s correct.

My current settings are:

Gsync enabled as Windowed and full screen mode since WoW only supports that.
Vsync On in NVCP
Vsync and triple buffering Off in game
Low Latency mode Off
Monitor set at 165hz OC, 162 in game

Hope to hear from you, thanks.

JanDev
Member
JanDev

Hey, thank you for this really good guide!

I do have two additional questions regarding input lag. It is implied in a video of Battle(non)sense that having the GPU sitting at a 99/100% load the input lag increases drastically. So my question would be: Is that so, and if yes would reducing the max framerate to bring the load to X% bring the input lag back to “best-case”?

Also, shouldn’t be “fast” VSync used over “on” VSync in NCP?

Unfortunately, I don’t have a setup to test this myself, so it would be great if you could give me an answer to that! 🙂

Greetings
Jan

nitro159
Member
nitro159

Firstly I want to thank you for caretaking these comments for so long and updating your guide with the changing names of the technologies involved.

Secondly, like many commenters, I have a unique situation (I think) and want to clarify some points for myself. AMD Ryzen 7 3700X paired with an Nvidia RTX 2070 Super and some RGB lights.

Using optimal settings, G-SYNC on, V-SYNC on in NVCP as a baseline. All good as you’ve said so many times here.

If I intend on streaming or recording through OBS or shadowplay, I used to (prior to obtaining this beautiful LG 32GK650F and previously gaming on a 4K 50″ tv @ 60hz) cap my frames in GTA Online (online, known for having frame pacing issues due to server to client side rendering delays) to 60FPS using RTSS to give overhead for recording (keeping usage below 95% per OBS guides) and also stopping my GPU working overtime when it really doesn’t have to in GTA as I tend to stick to races and other less intense game modes. With the optimal settings as I’ve switched from V-SYNC in game to using the NVCP option, should I still use RTSS to cap, the 1 frame delay is a non-issue for me but is the NVCP frame limiter better or worse than RTSS? I’d like to have it easily switchable as occasionally I play it offline for giggles and like the higher FPS I get there (around 80-90 @ 1440p). Obviously this is a fairly unique scenario, and a similar one would be Hitman 2, I usually hit the 80-90 mark there too but have never needed an FPS limiter to give the GPU room to render (oddly enough, same settings in OBS). I am yet to play H2 on the new snazzy monitor but I wondered whether you had any thoughts as to the order and priority of settings here to ensure there is *some* headroom at times, or whether I should just add a note to my recording/stream checklist to engage RTSS limiter on games that need it after testing.

I enjoyed the long read of your article and I am sorry my comment is challenging it on word count! Stay safe!

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