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.



3072 Comments For “G-SYNC 101”

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HopelessNinersFan
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HopelessNinersFan

Hi!

Thank you for the guide, it’s definitely made life much easier for me. I do have some confusion though. I have a 4080 SUPER, 32 GB RAM, i9 13980HX, and 240 HZ display – I’m quite proud of it. It mentions to enable Reflex if available or Low-Latency mode if FPS doesn’t always exceed the refresh rate, but how does that fit with setting a FPS limiter to limit the FPS regardless? I apologize in-advance if I’m misinterpreting, I’m still relatively new to PC gaming on a more advanced level. Furthermore, is Reflex even worth it if my 4080 isn’t ever anywhere near getting pinned? I heard Reflex only has an impact if your GPU is at 99%. Thanks again!

Regards,

Herconomicon
Member
Herconomicon

Do you recommend v-sync set to ON globally or per application ?

Vizima
Member
Vizima

So, I’ve been doing a lot of testing over the past few weeks. My PC specs are: Intel Core i7-13700k and my monitor is an Asus 240Hz OLED. First off, I want to thank you for the guide, it started my hyperfocus of testing a lot stuff xD. I stumbled upon something peculiar while playing Apex Legends.

When I cap my framerate (I use RTSS for this) and enable both G-Sync and V-Sync in the NVIDIA Control Panel, and then select Reflex in-game, my framerate gets capped at 225, as the guide suggests. It feels incredibly smooth, but I noticed something strange – I could NOT bunny hop anymore (on controller). Turning off V-Sync allows me to bunny hop again, but I dislike the drop in smoothness, so I decided to try some other options.

The first thing I tried was disabling Reflex altogether. Despite expecting Reflex to reduce input delay, its absence actually allowed me to bunny hop again (which I consider an indicator of low input delay). Then, I decided to re-enable everything – G-Sync, V-Sync in NCP, and Reflex in-game – and capped my framerate in RTSS to 200. To my surprise, I found that I could bunny hop once again, experiencing low input delay and maintaining very smooth gameplay. Can anyone explain what’s happening here? Because with the exact same settings at 225, I couldn’t achieve the same result.

Here are my MSI Afterburner benchmark results while playing in-game:

200 FPS (capped in RTSS)
Average FPS: 198
1% Low FPS: 185
0.1% Low FPS: 166

Thanks a lot!

toby23
Member
toby23

If I have a 120 Hz monitor with G-Sync and can achieve 115fps average in a game, is there any negative to locking the framerate to 59fps with RTSS to lower power consumption and smooth out Frametime?
Running unlocked in MSFS results in the Frametime jumping around all over the place but locking to 59 fps makes it steady.

PS Super article, thank you so much for keeping it updated.

Ryan Le
Member
Ryan Le

In Sea of Thieves, I have V-Sync turned off, but there is also an option to set the buffering to either double or triple, and there’s no off option. I set it to double buffering, but do I still need to enable V-Sync in NVCP? Would the in-game double buffering option (with in-game V-Sync off) conflict with NVCP V-Sync since it’s also running on double buffering?

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