G-SYNC 101: External FPS Limiter HOWTO


In-game vs. External Framerate Limiters*

*As of Nvidia driver version 441.87, Nvidia has made an official framerate limiting method available in the NVCP; labeled “Max Frame Rate,” it is a CPU-level FPS limiter, and as such, is comparable to the RTSS framerate limiter in both frametime performance and added delay. The “Nvidia Inspector: 2> Frame Delay” setup detailed further below is legacy, and does not apply to the “Max Frame Rate” limiter, the setup of which is also now detailed below it.

As described in G-SYNC 101: In-game vs. External FPS Limiters, In-game framerate limiters, being at the game’s engine-level, are almost always free of additional latency, as they can regulate frames at the source. External framerate limiters, on the other hand, must intercept frames further down the rendering chain, which can result in delayed frame delivery and additional input lag; how much depends on the limiter and its implementation.

In-game framerate limiters, however, aren’t available in every game, and while they aren’t required for games where the framerate can’t meet or exceed the maximum refresh rate, if the system can sustain the framerate above the refresh rate, and a said option isn’t present, an external framerate limiter must be used with G-SYNC to prevent V-SYNC-level input lag instead.

RTSS is a CPU-level FPS limiter, and introduces up to 1 frame of delay, whereas Nvidia Inspector uses a driver-level FPS limiter, which introduces 2 or more frames of delay. See G-SYNC 101: In-game vs. External FPS Limiters for complete details, along with input latency tests comparing the two external solutions against an in-game limiter.

RivaTuner Statistic Server: <1 Frame Delay

RTSS is available standalone here, or bundled with MSI Afterburner here.

If only a framerate limiter is required, the standalone download will suffice. MSI Afterburner itself is an excellent overclocking tool that can be used in conjunction with RTSS to inject an in-game overlay with multiple customizable performance readouts.

Blur Buster's G-SYNC 101: External FPS Limiter HOWTO

RTSS can limit the framerate either globally or per profile. To add a profile, click the “Add” button in the lower left corner of the RTSS windows and navigate to the exe. To set a frame limit, click the “Framerate limit” box and input a number.

Nvidia Inspector: 2> Frame Delay

An unofficial extension of the official Nvidia Control Panel, Nvidia Inspector (download here) exposes many useful options the official control panel does not, including a driver-level framerate limiter.

Nvidia Inspector can limit the framerate either globally or per profile (more details on profile creation can be found here).

To set a frame limit, locate the “Frame Rate Limiter” dropdown in the “2 – Sync and Refresh” section, select the desired limit, and then click the “Apply Changes” button in the upper right corner of the Nvidia Inspector window.

Blur Buster's G-SYNC 101: External FPS Limiter HOWTO

As of Nvidia Profile Inspector version 2.1.3.6 and Nvidia driver branch R381 or later, a new “Frame Rate Limiter Mode” dropdown has been introduced with a “Limiter V2 – Force Off” option:

Blur Buster's G-SYNC 101: External FPS Limiter HOWTO

This option claims to reduce the limiter’s input lag; exactly by how much, and with what combination of settings, remains to be determined.

NVIDIA Control Panel: <1 Frame Delay

As of Nvidia driver version 441.87, Nvidia has made an official framerate limiting method available in the NVIDIA Control panel labeled “Max Frame Rate.”

To set a framerate limit, navigate to the “Manage 3D settings” section in the NVCP, locate the “Max Frame Rate,” entry, select “On,” set the desired limit, select “OK,” and finally select the “Apply” button after it appears in the lower right corner of the NVCP window.



1873 Comments For “G-SYNC 101”

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blaskovic
Member
blaskovic

Hi jorimt. I have a question for you. Sometime in older games (2011 – 2013) I have a drop frame from 144 to 140 or 144 to 135 and I notice this microstutter with G-sync but in other games if I have this drops (for example in Dirty Rally) I don’t see anything. My question is this: Why in some case (games) G-Sync seems works but in other circumstances (games) i see this microstutter? G-Sync shouldn’t avoid Microstutter? Thank you

stadiofriuli
Member
stadiofriuli

I’ve got a question. Got the Dell S2721DGF(A) which is G-Sync compatible, I’m running the monitor at 165Hz.

So what I basically did is to set a FPS cap @161 with RTSS.

Enabled G-Sync fullscreen in NVCP.

Enabled V-Sync in NVCP.

According to the guide V-Sync within the G-Sync range should still act like for native G-Sync monitors when it’s an official supported G-Sync compatible monitor.

What happens for me though is.

When V-Sync is enabled FPS cap at 158, not 161 as set in RTSS.

When I then disable V-Sync and have only G-Sync running it’s capped at 161 again.

So my question really is why this weird behaviour?

Should I activate or deactivate V-Sync in my case?

SvenL
Member
SvenL

Hi,
First of all, thank you so much for creating such an amazing guide. After reading through a few more questions arose.

I’m playing Warzone (FPS game) on a 1080p 144hz free sync monitor with an RTX 2080Ti graphics card. (I achieve 170-180 fps in game uncapped, which is above the refresh rate of my monitor)

My goal is to have a 100% tear-free gaming experience with the least amount of input lag to achieve the best possible accuracy.

First, I took over the following settings from you
NVCP: G-Sync & V-Sync: On

But when it comes to the FPS limiter, I’m still unsure which is best in my case. (Warzone also supports reflex)

In-Game FPS Limiter (141 FPS cap)
Reflex: On / On + Boost
RTSS / NVIDIA’s Max Frame Rate (141 FPS cap)

The question is which of these options has the lowest input lag and at the same time the most constant possible frame time. (I assume these 2 factors are especially important for FPS games)
Or what you think would be the best sweet spot out of all of these options.

With reflex activated (On + Boost), I noticed that the frame rate varies (around 138 fps). I’m not sure whether this will have a negative impact on my frame time or input delay, as I could easily achieve a constant 141 FPS with my graphics card. Should I then prefer the in-game FPS limiter or RTSS / NVIDIA’s Max Frame Rate over reflex?

Thank you very much

RoseGoldCrobat
Member
RoseGoldCrobat

I signed up here since you seem to know a lot about this. I have a very strange issue.

I have a monitor that is Gsync compatible and Gsync is on in fullscreen mode.

When I play certain games, the current ones I’ve seen it in are Red Dead Redemption 2 and Hitman 3 I would like to have gsync on and vsync on. The problem is when both settings are on at the same time my FPS caps to 72 fps, half of my monitor’s refresh rate. I don’t understand why this is happening. Could I be missing a setting?

Zehdah
Member
Zehdah

Hello. I have a new monitor, it’s a Samsung G7 Odyssey which is 1440p 240hz with Gsync. I’m wondering what you would recommend for optimal performance/gaming with that setup since it’s unlikely I will hit 240hz in a game at 1440p with a 1080ti, should I still follow the above instructions and cap to 237 along with vsync on in CP, off in game? Curious if there’s any extra things I need to do.

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