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.



3051 Comments For “G-SYNC 101”

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Indignified
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Indignified

Hello, why do pro players for fps games use uncapped fps instead of these settings? Are there any benefits to using uncapped fps?

Pyerimi
Member
Pyerimi

Also I wanted to ask about what to do in case if ingame FPS limiter has bad implementation and introduce microstuttering like in this case: https://www.reddit.com/r/horizon/comments/i5p6io/pc_psa_do_not_use_the_ingame_fps_limiter_use_rtss/

Should I still use ingame option or RTSS?

Pyerimi
Member
Pyerimi

Hello, thank you for comprehensive guide.
I have three questions. I am using AMD card and freesync premium monitor. I setup V-Sync in driver for every game and lock FPS ingame if there is an option to do so, if not RTSS.

1) Counter-Stike 2 has its own limiter in console, ex: “fps_max 141”. It limits fps, but frametime isn’t as perfect as it is when using RTSS which makes it buttery smooth. The FPS itself stays at 141.
In amd software I turn V-Sync for this game and disable it ingame, and limit fps as I mentioned above ingame.
The question is, is this horrible frametime graph considered a problem when using freesync or it isn’t noticiable while under freesync conditions?
Should I use RTSS and unlock framerate ingame instead?

2) There are games where the option to manually configure FPS value to a precise number is absent.
Only presets, like 30\60\200 and so on. And there is no option to unlock FPS, only these presets.
What to do in this case to limit it to 141? If I set it to 141 in RTSS, will it conflict with the ingame limiter if I set it to lets say 200?
Should we set ingame limiter to max available value in this case and then lock it in RTSS?

3) In Forza Horizon 4 FreeSync seems to be not working, I disable ingame vsync and unlock fps, then limit it to 141 in RTSS and enable vsync in AMD driver, but FreeSync is not activating, I look at monitor OSD and I see 144 hz instead of variable 140-141.
However, AMD driver sets FreeSync option to “AMD optimized” for every game, this option is basically a blacklist for games where freesync allegedly known to be not working properly.
When setting this option to “On” freesync activates and seems to work, but according to my tests it introduces some stutters every now and then.
But the problem is, when I don’t use freesync for this game and set ingame options by default to vsync on and 144 fps preset, I don’t notice any latency added by vsync, meanwhile freesync is not working there.
The question is, could FH4 implementation of Vsync be latency-free and is there any need to force freesync there?

thiezek
Member
thiezek

Hello, good afternoon. Excellent post, I only had one doubt, using a configuration of GSYNC ON + NVCP VSYNC ON and the in-game fps limiter at 237 (I have a 240hz monitor). What should I use in the NVIDIA REFLEX? ON or ON+BOOST? Taking into account that I am already limiting my fps to 237 in-game.
Thanks!

alex1994
Member
alex1994

Hello, I play a MMORPG CPU intensive game on 165hz monitor gsync and my FPS in Raids go as low as 30fps and because of it causes stutters i think. I have Gsync + Vsync ON + -3 FPS below is this best set up for me you think ? I have 7800x3D and rtx 4080 super. The game i play is super old released in 2007 and super badly optimized. I tried different settings and cant seem to figure out best settings for this game. I hope you can help me out <3

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