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.



3745 Comments For “G-SYNC 101”

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higorhigorhigor
Member
higorhigorhigor

In my tests with the AMD RX 6750 XT, an LG 180hz IPS monitor, on both Linux and Windows 11, I noticed that when I cap the FPS at 60, for example, in scenarios that could deliver 160 uncapped, what happens is that my GPU significantly reduces its clock speeds, and this creates instability in frame production, causing the refresh rate to fluctuate widely.

On Linux, in LACT (a program for managing GPUs on Linux), I created a profile for the specific game and activated a performance level option that keeps the clock speeds higher. This completely solved the problem that occurs when I limit the FPS far below what my GPU can produce.

On Windows, I haven’t found a similar option to this, but I also haven’t looked much since I’m not using Windows a lot. I came here to comment, so that in case you weren’t aware of this, it might help other users who feel they have this VRR disengagement issue even when the FPS seems stable in RTSS.

COLEDED
Member
COLEDED

Thanks for the detailed guide. Sorry if this is a mostly unrelated question, I ask because the power plan is mentioned in the conclusion section.

My default Window’s “High performance” plan puts my minimum processor state at 0% for some reason.

Is it a good idea to just use Bitsum’s highest performance plan from park control, which sets the Minimum processor state at 100%, all of the time? I haven’t seen an increase in idle CPU power consumption or utilization after changing to this profile

Does this setting actually changes anything?

PODDAH
Member
PODDAH

Before you read this, I’m sorry for wasting your time if this question has already been answered in the article or in the comments. I tried to read everything to the best of my ability and still am a bit confused because my English is not the best.

Hey, I’m just writing this to make sure that I’m using the best setting. I have adaptive sync on in my monitor’s settings, which enables me to use G-Sync, and then I have G-Sync compatible enabled and V-Sync enabled too on in NCP, and the preferred refresh rate is at application controlled. I tried checking the delay and everything in Fortnite, because it has a setting which lets me do that. This gives me the least amount of delay, and even if I change my preferred refresh rate to the highest available, it still pretty much gives the same delay. I also have my FPS cap in Fortnite set to 144 just in case. I tried other things, and either they give me screen tearing or more delay. I only have one question: is this good enough to get the least amount of delay without getting any screen tearing?

CyclesOfJosh
Member
CyclesOfJosh

Hi there! I just stumbled upon this through a YouTube comment section, thank you so much for your hard work!

I was about to test the optimal settings in Overwatch when I noticed that in the Nvidia settings, there is a second option for V-Sync called “Fast”.
Is there any information on how that interacts with G-Sync and if it will have the same effect as it does with regular V-Sync? Would love to see if there’s more information on this!

kdog1998
Member
kdog1998

I have a question about my monitors VRR and if you know if there’s a fix for this or if I possibly have a bad monitor?

I have on G sync as recommended by you, using a Riva Tuner fps cap of 60 for final fantasy xvi. I have a perfectly flat frame time graph per riva tuner, but my game feels extremely jittery when I move around, especially when moving the camera. I figured out that my monitors on screen display that shows what it’s refreshing at is constantly bouncing around when using g sync and adaptive sync on. It will bounce from 60 to 52 to 67 to 48 to 180 (which is my max refresh) back to 60 to 77 and etc.. so despite my game holding a locked in 60 fps with a flat frame time graph, my monitor doesn’t seem to be refreshing at 60 and it seems to be bouncing around.

Is this normal? Or did I just happen to get a bad monitor or graphics card? My monitor is the ASUS VG27AQ3A, I have had it for about 6 months and have been thinking from the beginning something may be off with it. Any help would be great!

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