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.



1462 Comments For “G-SYNC 101”

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BlackStorm82
Member
BlackStorm82

240Hz / GSYNC ON / 60FPS
240HZ / GSYNC OFF / 60FPS

Which is better in response time? Which one is better for blur?
G-Sync’s variable refresh rate function Does the screen response speed also affect it?

swaz
Member
swaz

Hi,
NVIDIA recently introduced a new “Max Frame Rate” setting in its Control Panel.
So I’m wondering if that uses the same FPS limiter tested via “Nvidia Inspector” on page 11.
If that’s not the case, when an in-game framerate limiter isn’t available, should I use RTSS or this new setting?
Thanks in advance.

DrGoku4star
Member
DrGoku4star

I’ve noticed more and more game now are ditching “Fullscreen exclusive” mode now such as Wow (World of warcraft) and Cod (Call of Duty) cold war and Rust.

One way i verify this is buy moving the volume scroll on my keyboard, and if i see the windows volume overlay appear in game, it’s not full screen exclusive?

Anyway, my main question is, with what i just said in mind, isn’t it better to leave The “Full screen optimizations” box ticked now? So that the DWM bypasses triple buffed v-sync?

Talos-LXIX
Member
Talos-LXIX

Hello there!
First i just want to say thank you so much for all the amazing work you guys do. in-depth analysis and guides like this are really helpful.

I just have a few things that I’m not entirely sure about.

1) You’ve found that G-SYNC completely bypasses the 1 frame of delay add by DWM in windowed/borderless. is that only the case if you’re within the G-SYNC range with V-SYNC enabled? could you still bypass it if you ran G-SYNC with V-SYNC off while being over your monitors refresh rate?

2) is G-SYNC+ V-SYNC off with fps over the monitors refresh rate identical to G-SYNC off + V-SYNC off?
For some reason some games (Apex Legends for example) lock their fps to my monitors refresh rate (120) when i try to disable G-SYNC via the per program settings on the NVCP.
I typically like to disable it for competitive FPS games as i can get much higher FPS than 120.

Hiram
Member
Hiram

Hello, I have read a lot, but I have a question.
In my case I play Fortnite, and if I limit the fps to 144 in the game and in the NVCP the screen tearing is not very noticeable, but it happens, otherwise if I play at limited 120 fps the screen tearing is much more noticeable, ( also putting 120hz in the NVCP).
Of course, my fps are not very stable when I get into a fight, they drop from 120 to 100 or a little less.
My question is, do I have to have V-sync activated?
I hope you can answer me

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