G-SYNC 101: External FPS Limiter HOWTO


In-game vs. External Framerate Limiters

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.



662 Comments For “G-SYNC 101”

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BlackStorm82
Member
BlackStorm82

HI
“fixed refresh rate”
Do you have information about?

Is it correct that G-Sync does not work when I use this?
In-game [frame limit release mode]
When it comes to monitor technology G-Sync, 100-600 FPS was also released.

[fixed refresh rate]
When I activated the League of Legends with this function, 300FPS was fixed.

rocet
Member
rocet

Hi, maybe i’m misreading or misunderstanding the graphs/article but there is no downside to just using G-Sync ON + V-Sync OFF + No fps limit?

G-sync would activate when below 144fps and then ‘de-activate’ above 144? Causing no input lag?

Zehdah
Member
Zehdah

I know that for the lowest possible input lag, you want to find the highest framerate your system can achieve an average of 95-99% of the time without maxing your GPU usage and cap your framerate there with an in game limiter, but what do I do to achieve that in a game like Warzone where my FPS can be as low as 140 in big open areas or as high as 240 when inside a building or small area?

My CPU and GPU usage always seem to be very high at 85-97%. I have an i7 9700k and 1080ti, playing on a 240hz monitor. The game seems to be poorly optimized so I’m struggling to decide what to do.

fanatycme
Member
fanatycme

When I play DOTA 2, my fps is all the time at ~117 because i capped it, but at the end of the game, when match finishes the base gets destroyed and i get a FPS DROP from ~117 fps to 80-90 fps and my game STUTTERS, is it normal? i am playing with g sync, vsync and fps cap, i thought gsync is supposed to GET RID of stutter or I do SOMETHING WRONG?? during the rest of the game everything seems ok

i am using:
-nvcp: gsync on fullscreen, highest refresh rate, vsync let 3d app decide
-dota2: vsync on, fps max 117 (120hz monitor), highest video settings
-latest drivers, gtx 1070, monitor aw3418dw

AnonymousH
Member
AnonymousH

I typically prioritize input latency and thus normally run with G-SYNC but without any framerate limit or V-Sync, which causes some tearing at high framerates. I initially thought that Fast Sync eliminates tearing but introduces some microstutter, and that was all, making it a viable option in combination with G-SYNC, and the rest depends on preference (with G-SYNC: none = tearing, V-Sync + framerate limit = higher latency, Fast Sync = microstutter). However, if I’m reading this correctly, even G-SYNC + Fast Sync without a frame limit isn’t recommended because it limits the framerate to something lower than the monitor refresh rate, or runs starting at that slightly lower framerate?

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