Next

G-SYNC 101: Control Panel

Published Jun 20, 2017 by in: G-SYNC

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.”

Next

3747 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
HotChocolate
Member
HotChocolate

H, Jorimt.

I have a 240Hz G-sync compatible monitor (Odyssey G7), but my game of choice (PUBG) has a hard time keeping anywhere near stable frame rates. 0.1% lows are around 80 and 1% lows are around 110, despite my averages being 190+. As a result I lock my frames at 140 in the in-game limiter to reduce frame variance.

My question to you is:

1. Should I run my monitor on 144Hz or 240Hz? I currently run it at 144Hz?

2. If I run it at 240 Hz, will there be any benefit at all from enabling Vsync?

And some additional unrelated questions:

3. I see you recommend Low Latency Mode. Why not Ultra Low Latency Mode? S

4. Should I keep LLM disabled if my GPU usage is well below 100% usage?

5. Does Vsync + Gsync + LLM work when the game is run in Borderless Mode, rather than Fullscreen? If no, care to elaborate?

Hopefully you can answer some of my questions above. Thx.

Like0Vote Down 
3 years 10 months ago
jorimt
Author
jorimt

Should I run my monitor on 144Hz or 240Hz? I currently run it at 144Hz?

For the fastest frame delivery with G-SYNC, regardless of framerate, always use the max available refresh rate. In lowering it to 144Hz, frames are now scanning in at 6.9ms per instead of the 4.2ms per they would be at 240Hz with G-SYNC.

Basically, you’re reducing the effective G-SYNC range and slowing frame delivery with a lower physical refresh rate.

It’s also possible your display has more processing latency at 144Hz vs 240Hz, so unless you’re using the lower refresh rate for overdrive performance purposes due to the lack of variable overdrive on G-SYNC Compatible FreeSync displays, there’s no reason to do so.

If I run it at 240 Hz, will there be any benefit at all from enabling Vsync?

In combination with G-SYNC with framerates within the refresh rate? Yes, no tearing. Up to you.

I see you recommend Low Latency Mode. Why not Ultra Low Latency Mode?

I don’t necessarily recommend Low Latency Mode. My optimal settings say if you must use LLM with G-SYNC, use “On” instead of “Ultra” so you can control the framerate limit yourself.

LLM “Off” is also fine with G-SYNC. It depends entirely on whether the given game’s engine allows LLM to function, and if it does, whether your system is capable enough to improve performance with LLM enabled.

Should I keep LLM disabled if my GPU usage is well below 100% usage?

Depends on if the game supports it, your system doesn’t introduce more stutter with it engaged in the given game, and yes, if your GPU usage is maxed or not. If it isn’t, LLM will do nothing to reduce latency further.

5. Does Vsync + Gsync + LLM work when the game is run in Borderless Mode, rather than Fullscreen? If no, care to elaborate?

Again, LLM is not directly G-SYNC related, and it’s usage can depend on a variety of factors.

LLM honestly isn’t very impactful, and isn’t terribly important where latency reduction is concerned, even in the best of times. Reflex is its far superior replacement by the way, so if your system tends to be GPU limited in a game that supports Reflex, use it instead of LLM.

As for G-SYNC + V-SYNC with borderless/windowed mode, if it’s traditional borderless/windowed not affected by MPO, then DWM composition V-SYNC will act in place of NVCP or in-game V-SYNC, typically.

That said, having V-SYNC enabled in-game or in the NVCP won’t negatively affect that scenario either, since it will either not apply on top of the DWM V-SYNC, or it will override it, but both should have the same effect regardless; strict adherence to the VBLANK as to avoid tearing at all times during G-SYNC operation.

Like0Vote Down 
3 years 10 months ago
Ditto7654
Member
Ditto7654

Hi Jorimt,

I have a few questions for you if you ever get the time. I have only one game I play and I find that it’s borderline impossible to get it to run properly with G-sync; Apex Legends.

I play on a 240hz G-sync monitor, and have also used many others. All with no luck, even after following these guides + guides in r/competitiveapex

I’d like to start with just 2 questions

1. ) Why is V-sync required, if I am capping extremely far below the max refresh of my monitor? IE: 190-180 FPS. There is absolutely no chance that my fps will get close to 240 or above (causing screen tear) and as I understand, Nvidia now allows G-sync usage with OR without V-sync enabled in NVCP?

2. ) When using Nvidia Reflex, which is available in apex legends, is this using the game engine as a limiter? Or is it capping the framerate at the NVIDIA driver level?
I ask this because nvidia reflex cap seems to have not very stable frametime delivery, so generally I try to cap again with RTSS which now means I have a triple frame rate cap; V-sync caps at 240, reflex caps at 224 (for a 240hz monitor) and then generally I use RTSS at 1-2 frames below the reflex cap. Doesn’t multi capping a game like this generally cause unwanted issues?

I apologize for the length of this post but I have had my PC for a year, and gone through 3 different monitors with no luck. Apex runs choppy when holding stable fps & when dipping and I’m at wits end here to get a smooth gameplay experience.

Thanks for any and all help, hope you have a good day!

Like0Vote Down 
3 years 10 months ago
jorimt
Author
jorimt

Why is V-sync required, if I am capping extremely far below the max refresh of my monitor? IE: 190-180 FPS. There is absolutely no chance that my fps will get close to 240 or above (causing screen tear) and as I understand, Nvidia now allows G-sync usage with OR without V-sync enabled in NVCP?

It will still tear during frametime spikes with G-SYNC on + V-SYNC off. Said combo will only prevent tearing when a frame is in time. If it’s too late or too early, it will tear.

G-SYNC + V-SYNC will prevent tearing whether a frame is in time, early, or late.

When using Nvidia Reflex, which is available in apex legends, is this using the game engine as a limiter? Or is it capping the framerate at the NVIDIA driver level?
I ask this because nvidia reflex cap seems to have not very stable frametime delivery, so generally I try to cap again with RTSS which now means I have a triple frame rate cap; V-sync caps at 240, reflex caps at 224 (for a 240hz monitor) and then generally I use RTSS at 1-2 frames below the reflex cap. Doesn’t multi capping a game like this generally cause unwanted issues?

Reflex’s limiter is at the engine-level. It does not use Nvidia Max Frame Rate’s driver-level limiter. So no, it won’t always have as steady frametime as external limiters like RTSS, because it doesn’t limit by frametime, which is part of why it’s lower latency, but part of why, in turn, frametime performance is less steady.

As for having a “triple” framerate limit, you don’t. V-SYNC can’t actually be considered a framerate limit, and with G-SYNC enabled, so long as the framerate is below the refresh rate, standalone V-SYNC behavior won’t ever engage.

So that just leaves Reflex and RTSS in your case….

Now, you’re correct that “multi capping” isn’t advisable, but it’s only “bad” if you’re capping multiple limiters at or near the same limit. It’s fine if you’re trying to override an in-game limiter with an external limiter so long as it’s a couple or more frames below the other.

That said, whenever the framerate drops below your RTSS limit, the automatic Reflex limiter kicks in and dynamically sets its limit to a level that prevent max GPU usage. I.E. if all your system can sustain in the given scene is 137 FPS, Reflex will limit to, say, ~134 to prevent the GPU from hitting 99%+.

If you’re looking for more consistency with Apex when using G-SYNC, the only answer is to find your lowest average framerate and cap just below that with RTSS. So long as the average framerate never drops below your limit (and the GPU usage doesn’t max), things will feel much steadier than say, ~220 FPS 70% of the time, and fluctuating framerates below it 30% of the time.

If you are able to set a limit that your system is capable of maintaining 99% of the time in Apex, then you won’t need Reflex on top of it, as said option is only fallback for when the framerate isn’t being limited by anything else (which means the GPU is the limit at that point; again, something you want to avoid for latency reasons).

Like1Vote Down 
3 years 10 months ago
touron21
Member
touron21

Hi all,

Bit of a strange question, I’m hoping one of you may be able to help.

I have a G sync compatible 165Hz 1440p monitor and play most games on my desktop with G sync and V sync ON, with an FPS cap of about 158. Everything runs well and feels buttery smooth.

Then when I play on my laptop (Asus Rog Strix Scar 15, 2021 model) connected via USB-C to DP, also with G sync and V sync ON, it just doesn’t feel as smooth. My laptop is almost as powerful as the desktop and can maintain 157fps in Apex 90% of the time, so a difference in fps between the machines isn’t the issue. The cable I’m using is DP 1.4, connected directly into the laptops RTX 3070 via USB-C, so I feel that cable quality isn’t the issue either. Settings in game and in nvidia control panel are identical also.

Does anyone have an answer as to why it feels so much less smooth?

Thanks in advance.

Like0Vote Down 
3 years 10 months ago
jorimt
Author
jorimt

I don’t have a lot of hands-on experience with laptop G-SYNC in particular (which I believe is software, not module-level), but since it sounds like you have everything configured properly on your laptop for G-SYNC usage with your desktop monitor, I’d chalk it up to whatever differences there are between laptop-specific G-SYNC implementation and desktop G-SYNC Compatible implementation.

How does G-SYNC feel on the laptop’s built-in screen in comparison? And have you verified that G-SYNC from the laptop is indeed engaged and active on the G-SYNC Compatible desktop monitor during gameplay?

Like0Vote Down 
3 years 10 months ago
touron21
Member
touron21

Hey, appreciate the reply. G sync is engaged on the laptop yes, I checked using the indicator from nvidia control panel. G sync feels OK on the laptop, but definitely not great, and worse than using the external monitor.

I didn’t realise G sync was software based on laptops, so I think the difference in implementation must be the cause. For now I’ll just use the desktop as much as I can!

Thank you again for the reply, appreciate it!

Like0Vote Down 
3 years 10 months ago
jorimt
Author
jorimt

You’re welcome.

Like0Vote Down 
3 years 10 months ago
Linkaran
Member
Linkaran

Hey !

I have a question regarding GSYNC on LG CX with games capped at 60FPS

Currently I have GSYNC enabled in my windows and I set the FPS to 117 and I enable VSYNC in the nvidia control panel for all my games

However, for games capped at 60 FPS, should I disable GSYNC to avoid flickering? The game I’m currently playing is stuck at 60 FPS max and I don’t have any framerate drops so technically GSYNC isn’t useful in this kind of case and should I disable it or leave it? because I have a little flickering

Like0Vote Down 
3 years 10 months ago
jorimt
Author
jorimt

I own the CX as well. Flickering on that OLED panel is due to a fixed gamma curve at the hardware-level. When VRR is engaged, it adjusts the refresh rate dynamically, but since there’s only one internal hardware gamma settings tuned to the max refresh rate, if the refresh rate fluctuates too rapidly during VRR operation, flicker at the lower end will become visible.

The only way to avoid this, is to keep the frametime performance as steady as possible. You can achieve this with an RTSS or Nvidia Max Frame Rate limit.

As for G-SYNC not being “useful” in your 60 FPS scenario, assuming you want tear-free gameplay, there’s no other method that will be lower latency; G-SYNC is just as beneficial at a fixed framerate as it is at a variable framerate within the refresh rate.

Like0Vote Down 
3 years 10 months ago
Linkaran
Member
Linkaran

OK thank you for your answer !

So in cases where games are capped at 60FPS max with the LG CX, which options do you recommend?

GSYNC ON + VSYNC ON + 57 FPS CAP?
GSYNC OFF + VSYNC ON?
GSYNC OFF + limitation to 60 Hz?

Like0Vote Down 
3 years 10 months ago
jorimt
Author
jorimt

Depends on the game. What’s the title?

Like0Vote Down 
3 years 10 months ago
Linkaran
Member
Linkaran

The game is Blasphemous

but in general there is no unique configuration for games stuck at 60fps max?

Like0Vote Down 
3 years 10 months ago
jorimt
Author
jorimt

Each game/engine nearly always has a unique configuration for how it’s at 60 FPS, and whether it can be defeated.

In this particular case, I took a look; Blasphemous runs on the Unity engine, and presumably uses it to limit internally.

The demo originally ran uncapped, but key mechanics were breaking with an unlimited framerate, so the devs set a hard limit of 60 FPS to prevent engine issues.

Some 60 FPS games that require the limit to not break, can be bypassed and disabled, at which point an external limiter of the same limit can be used in its place.

Since you’re experiencing VRR flicker on the CX, which is due to unsteady frametime performance, my hope was you could disable the in-game limit, and set an RTSS or Nvidia Max Frame Rate limit instead, which should have steadied the frametime performance enough to avoid flicker.

Since it doesn’t look like there’s a simple option to disable the internal limiter in this game, assuming you want the lowest lag tear-free experience:
 

  1. Navigate to %USERPROFILE%\AppData\LocalLow\TheGameKitchen\Blasphemous\Savegames\\options_settings.json and see if there is any FPS limiter parameter that can be set to “0” or disabled. If so, keep G-SYNC + V-SYNC enabled, disable the internal limit via the config file, and set a 60 FPS limit via RTSS or Nvidia Max Frame Rate instead to see if that reduces or eliminates flicker on the CX.
  2. If #1 isn’t possible (probably won’t be), the next lowest latency tear-free option is RTSS Scanline Sync. In this case, disable G-SYNC, set the max refresh rate for this game to 60Hz, and then follow the below directions to configure Scanline Sync (warning; it can be touchy): https://forums.blurbusters.com/viewtopic.php?f=10&t=4916#p38019
  3. If you don’t want to bother with Scanline Sync, the next best lower latency tear-free option is to again disable G-SYNC, set the max refresh rate to 60Hz for this game, but then use the low lag V-SYNC method explained in this article: https://blurbusters.com/howto-low-lag-vsync-on/
  4. Finally, if you want a “set-and-forget” tear-free option without worrying about any of the above, but with some additional latency, disable G-SYNC, enable V-SYNC, and lower your max refresh rate to 120Hz for this game. It will still run at 60 FPS, but each frame will at least repeat in even intervals at 120Hz (will display each unique frame twice in a row), instead of the uneven intervals at 144Hz, which would create recurring stutter.
Like1Vote Down 
3 years 10 months ago
Linkaran
Member
Linkaran

Damn man thank you for taking your time to research the game and especially for your very detailed answer

It’s much clearer to me now for games like Blasphemous
Most of the time I always use the GSYNC + VSYNC + 117 FPS configuration and this is the first time that I came across a game limited to 60 FPS which made me return to your article

The LG CX is an amazing screen but it’s a shame that there are some flickering issues with GSYNC, otherwise it would be really perfect

Have a great day and thank you again for your response.

Like0Vote Down 
3 years 10 months ago
jorimt
Author
jorimt

Sure, no worries.

Like0Vote Down 
3 years 10 months ago
Linkaran
Member
Linkaran

I have one last little question with VSYNC only without GSYNC, between a game with an unlocked framerate that is to say that it runs between 50 and 120fps on a 120hz screen is it better to put the screen in 60hz and limit the game at 60fps or leave the screen at 120hz and the framerate unlocked?

Like0Vote Down 
3 years 10 months ago
jorimt
Author
jorimt

That’s ultimately preferential. Both aren’t great.

Between the two, for standalone V-SYNC, 60Hz 60 FPS will feel more consistent due to the locked framerate. 120Hz 50-120 FPS will feel smoother sometimes, due to the higher refresh + framerate, but unless the game has some form of triple buffer V-SYNC, it will lock the framerate to half refresh (60 in this case) whenever the framerate drops below 120.

For 120Hz uncapped V-SYNC, you could try Fast Sync if standard NVCP V-SYNC or the game’s V-SYNC does so.

Like1Vote Down 
3 years 10 months ago
Gbcrespo
Member
Gbcrespo

Great information overall, keep up the good work informing the Internet. It’s amazing how this isn’t talked about enough about Gsync and Vsync, and how many people are utilising it wrong.

I couldn’t quite find in the article one info. When you have a game that fluctuates between 70-90 fps for example (a situation where GPU can’t quite reach the monitor refresh rate) in a 144Hz monitor, what would be the ideal way to play in a Gsync monitor?

I’ve been playing Red Dead Redemption 2 capped at 60, but my GPU can push it to 80-85fps. In my last monitor that didn’t have Gsync, when I disabled vsync, I used to receive a lot of screen tearing and it was unplayable for me. Now with a monitor with Gsync, I still receive tearing with vsync disabled (far less but it’s definetly there). One thing that helped a lot though, is when I cap vsync at 60 is smoother than my last monitor (no small stuttering when GPU load drastically change).

Should I use a program like RTSS to set the game to a desirable fps limit? RDR2 framecap after 60 is 100, so I can’t do this in-game.

Like0Vote Down 
3 years 10 months ago
jorimt
Author
jorimt

When you have a game that fluctuates between 70-90 fps for example (a situation where GPU can’t quite reach the monitor refresh rate) in a 144Hz monitor, what would be the ideal way to play in a Gsync monitor?

G-SYNC + V-SYNC prevents tearing with framerates within the refresh rate without creating additional latency or stutter.

It will have no problem with variable framerates, such as 70-90 at 144Hz, but if your GPU usage becomes maxed at any point, render queue latency (unrelated to G-SYNC operation) will increase.

To avoid this, use an FPS limit that prevents max GPU usage in the given game, or use Reflex where available. Both will do the same thing; the RTSS or Nvidia Max Frame Rate limiter simply must be set manually, whereas Reflex will set an automatic FPS limit.

Like1Vote Down 
3 years 10 months ago
wpDiscuz

Related Content

Featured Content

Blur Buster Forums

Blur Busters Forums

TestUFO Motion Tests

TestUFO Motion Tests