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.



3723 Comments For “G-SYNC 101”

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olam
Member
olam

Hi thanks for you guide!

Is it recommended to disable G-SYNC on my other monitors which support G-SYNC?
Only my main monitor runs at 360Hz, while the other two run at 240Hz.

My actual issue is that my games don’t feel as smooth as they should.

Thank you in advance.

Hena
Member
Hena

Quick question, is it normal for a game like Final Fantasy XIV to have a laggy mouse cursor with GSYNC + NVCP V-Sync, it’s not the case when I deactivate GSYNC, it’s weird despite the fact that game has an option for hardware mouse cursor, or is it just the intended behavior with GSYNC ?

user2422
Member
user2422

I’ve read below that you personally disable the windows VRR option. Is there a specific reason for that? If i remember correctly, you said in an older comment that this setting is not directly related but it doesn’t hurt to leave it enabled for any edge cases.

Jokerstarik
Member
Jokerstarik

Hello! Thanks for your article. Could I ask your opinion based on your experience?
I have a TCL C805 TV in Game Mode with VRR enabled. My RTX 5070 Ti runs with G-Sync on, and V-Sync is enabled in the driver. I use Frame Generation (×2 and ×3) to reach 138 FPS. Reflex limits it to 138 FPS automatically.

Here’s my issue: with DLSS 4 I get a stable 63 FPS, but when using ×2 generation I don’t reach 138 FPS. With ×3 I do, but Reflex seems to cap the base render to around 46 FPS—the rest is generated. I can see this when disabling generation: FPS locks at 44–46 and GPU load stays at 65–70%.

How can I remove this base render limit so the GPU renders around 60 real FPS, and Frame Generation raises it to 138 FPS?
(V-Sync, G-Sync/VRR, Reflex + Multi-Frame Generation enabled.)

kdog1998
Member
kdog1998

regarding low latency mode and reflex, when exactly do i turn them on or off? I use RTTS and set a fps cap to 65 in a game, my gpu hits that easily so i can maintain smooth gameplay. Do i still need to have a low latency mode enabled? would i set it to on or ultra or neither? in another game, i either exceed or sometimes sit just below my max refresh rate, do i need to use either reflex or low latency mode if available?

I have also noticed something weird when it comes to fps caps and im not sure what causes it, if its my monitor specifically or g sync. In example god of war ragnarok, i was able to hit 160 fps uncapped and when i would rotate my camera it was buttery smooth. But if i added a fps cap, even if it was 157 fps the camera panning was unsmooth and seemed excessively blurry. I tested this by going to a hard to run area, and uncapped my fps. at uncapped 120 fps camera panning was smooth , but if i placed a fps cap at 120 and panned it was wrong weird again. it only happens with a fps cap in place. ive tried it with ultra and on low latency mode and both have the issue, but i have not tried it off completely. I hope this makes sense and doesnt seem like rambling lol

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