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.”



2218 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
AgentDaumer
Member
AgentDaumer

G-SYNC reverts to V-SYNC behavior when it can no longer adjust the refresh rate to the framerate, 2-6 frames (typically 2 frames; approximately an additional 33.2ms @60 Hz, 20ms @100 Hz, 13.8ms @144 Hz, etc) of delay is added as rendered frames begin to over-queue in both buffers, ultimately delaying their appearance on-screen.

I’m surprised that a framerate limit just 2-3 FPS below the monitor’s refresh rate can actually prevent G-Sync from hitting that threshold and reverting to V-Sync behaviour. Using RTSS I noticed that a 140 FPS cap (in-game) will still allow the framerate to fluctuate and reach pretty high values, often higher than 160 FPS. Even a 120 FPS cap still exceeds 144 every couple seconds.
It happens intermittently of course, the frametimes are constantly fluctuating (as they should) and the average framerate is still respecting the limit.
However, wouldn’t those big spikes mean that G-Sync is frequently engaging and disengaging all the time? Am I missing something?

Unneverseen
Member
Unneverseen

How is the latency for competitive fps games with 141fps limit (i have 144hz monitor) and Gsync and nvcp vsync on? should i disable fps limit and nvcp vsync for less latency? also do you set Max Frame Rate, low latency mode, and vsync globally or per game basis? also i heard that fps limit improving latency depends on the game, some it might give worse latency some its better latency. thanks for the article

YormFatigue
Member
YormFatigue

Hello Jorimt, thanks for your article, it’s great, now I know more about this kind of Technology and am less confused of it.
But anyway, I want to confirm something, and hope you will answer it.
I use Freesync monitor 144HZ, based on what I learn, so it’s just the same as G-sync. When I play games, one thing I absolutely want to get rid of is microsutter, even after using VRR, I still have it to this day, when reading your article, I think I know the cause, and I know it may be unavoidable, but I want to be clear to it. So, these are my cases:
– When I play some games, I suffer occasional microsutter and sometime occasional tearing, of course I turn Freesync on, but it still remains as is, turning on V-sync will make that “occasional tearing” become microsutter as well, using fps limiter to limit the fps which is far lower than what point my specs can archive. My question is what makes that behavior? Is It the game’s problem that creates great frametimes variance and frametimes spikes? And additional info, some games I played have are kind of weird, that the lower fps is, the smoother the game is,
– There are also games that will present microstutter no matter what fps is, take an example of The Witcher 3, my specs can reach 60+ fps, so good idea that I should cap it just to 60 (I do it in almost game anyway) and it still has microstutter, then I tried to apply the weird way I state above, tried lowering fps, as low as I can play (well – 30fps), and still no good, microstutter is still there. So is it my system’s fault or the game’s fault?
And one last thing I want to share, based on what I’ve experienced so far (not read or learn), is I am pretty sure that fps limiter can somehow help Freesync in terms of smoothness, even it is below the targeted fps. I am talking about AMD framerate target control – FRTC for short, which is the smoothest framerate limiter (and It comes with the biggest latency), on my test, In the same game, in the same place of the game, I used 4 fps limiter: In-game, Chill with max-min equal, RTSS, FRTC, I saw that with FRTC, there is almost no microstutter no matter what fps, Chill and RTSS are pretty same as each other – comes with microsutter, but Chill does have less than RTSS and RTSS seems to have little smoother images when rotating camera, in-game is the father of microstutter.
I find that interesting, and I turn off Freesync to see what would happen. Well, with FRTC, tearing would present as one line tear which is incredibly stable, if fps can reach the target, even below tearing is still pretty stable. With Chill, tearing at almost time will present as two pretty small tearing at two position of the monitor, one upper and one lower. With RTSS, tearing gathers its power at one position of monitor and “dances” at that point. This behavior applies to almost all games, or so I’ve seen so far, and with that information, I think it is not silly to assume that fps limiters somehow affect or help Freesync or G-sync.
Thanks for taking your time to go through my long comment, there are maybe mistakes as English is not my primary Language, hope I did not make too much of it.
And Happy New Year.

nidzo
Member
nidzo

Hello, so I’ve been trying to get my game to run more smoothly and I have a few questions about how gsync and nvidia reflex and all that works. I’ve been capping my fps to 141 with reflex on and gsync and there’s no problem for the most part, but when my fps starts to fluctuate (100-141 fps) it feels very choppy. SO i was wondering, would it make more sense to limit my fps to something like 100 FPS so that I’m still in gsync range but my fps is more consistent or should i just keep it capped at 141 and let the game reach that fps every once in a while. I’ve been trying for a while to try to get this game as smooth as possible on my poopy machine lmao. Thanks.

Divij
Member
Divij

Thank you for this amazing article.

I am struggling to find the optimal settings for my set up to play Microsoft Flight Simulator. Anything above 30 FPS works well as long as it is stutter and lag free.

The refresh rate for my monitor is 144hz and I have capped the FPS to 35 in Nvidia Control Panel. G Sync is enabled and V Sync set to On in Nvidia Control Panel.
V sync is off in game.

Another option is to use 100hz refresh on my monitor and use in game V sync to 1/3rd of my monitor refresh rate which locks the FPS at 33. This way I do not need to lock the FPS in the Nvidia Control Panel. The only in game V Sync options are (locked at refresh rate, half refresh rate & 1/3rd refresh rate)

Which of the two options would you recommend for stutter, lag free and overall best experience?

Thank you for all your help!

wpDiscuz