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/App; labeled “Max Frame Rate,” which 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 Profile 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 Profile 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 Profile Inspector: 2> Frame Delay

An unofficial extension of the official NVIDIA Control Panel, NVIDIA Profile Inspector (download here) exposes many useful options the official control panel does not, including a driver-level framerate limiter.

The NVIDIA Profile 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 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/App: <1 Frame Delay

As of NVIDIA driver version 441.87, NVIDIA has made an official framerate limiting method available in the NVIDIA Control Panel/App labeled “Max Frame Rate.”

To set a framerate limit, navigate to “Graphics” in the NVIDIA Ap or “Manage 3D settings” in the NVCP, locate “Max Frame Rate,” select “On,” set the desired limit, and select “Apply,” or “OK,” then “Apply.“



3896 Comments For “G-SYNC 101”

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Sort by:   newest | oldest | most liked
Robi
Member
Robi

Hey Jorimt, i did some testing again and found that in Cyberpunk2077 Frame Gen increases your latency in less gpu demanding areas, what do you know about this?

Here is my testings:

Question: Does DLSS Frame Generation increase PC Latency when GPU utilization decreases? (Cyberpunk 2077)

My settings:

– DLSS Super Resolution: Quality Transformer Model 2
– DLSS Frame Generation: 2×
– FPS cap: 157 RTSS (Async)
– NVIDIA Reflex: enabled (By default when FG)
– G-SYNC and V-Sync (NCP) configured correctly
– All graphics max + Path Tracing

My observations:

– In demanding areas, NVIDIA overlay PC Latency is around 35 ms.
– In less demanding areas, PC Latency rises to around 55 ms, despite lower GPU utilization.
– With Frame Generation disabled, I get around 100 FPS and 26 ms average latency.
– Interestingly, switching to DLAA while keeping Frame Generation enabled increases GPU utilization and reduces latency again but only in the less gpu demanding area.

I’ve repeated these tests, and I can feel the difference in responsiveness, I play lots of FPS games and I can physically feel the difference between 35ms and 55ms this is not a margin of error from Nvidia Overlay LAT.

Has anyone observed Frame Generation causing higher latency at lower GPU utilization?

wbotter
Member
wbotter

Hey! Wondering if V-Sync is applicable to Gsync Pulsar monitors? I just got one, went from PG27AQDM to the XG27AQNGV after receiving not one but TWO defective PG27AQWP-W’s!!! After the second AQWP-W started intermittently dropping signal due to the UHBR-20 handshake failing, works flawlessly in UHBR-13.5 with DSC, but for a $1250 monitor, I’d expect it to work as intended. So, I ultimately gave up on the flagship and was just searching for 27″ or less 1440p monitors over the 240hz my AQDM was already giving me, and the Gsync pulsar caught my eye. I had a BenQ Zowie with DyAc+ a few years ago and loved it, so yeah the curiosity got me with this monitor. I currently have a 9800x3d, cl 28 32gb 6000mhz, and a 5070. (Yes, Ik my gpu is hardcore limiting my FPS). I play competitive games mostly, in “comp settings” (basically low everything), DLSS Quality or Balanced using Model K, and I’ll get 384fps peaks, 271 avg, 202 1% lows and an average PCL of 10. All captured using frameview in marvel rivals after many many many “change one setting,” *capture for 45min-1hr of gameplay,* did this increase or decrease performance? lol! (All without DLSS FG. I’m not opposed to DLSS FG 2x, but 3x and above my PCL climbs quite a bit.)

Anyways, got any advice to get the most out of the GSYNC Pulsar Monitors? Or same rules apply? Thanks!!

user2422
Member
user2422

In an earlier comment you mentioned that ULLM is somewhat inefficient compared to Reflex or a manual limit, if i were to use Gsync + Vsync + ULLM, would that starving of the max queued frames and the potential stutters that come with it even apply considering that ULLM is auto limiting the fps in this configuration? Like does it limit low enough to prevent this from even happening?

Also when using Gsync + Vsync and then only enabling ULLM via Inspector without setting max pre-rendered frames to 1 (which ULLM would’ve otherwise done if it was applied via NVCP or NVApp), would this then be just an auto limiter without the other effects of ULLM? I’ve tried this configuration in-game and the auto limit still applies but I’m unsure whether or not ULLM will have any other impact in this configuration.

eonjr
Member
eonjr

Hi, thank you for the guides! But I have something to ask. My laptop has a 300hz refresh rate that is also GSync compatible. I have it capped at 285 using a formula that I saw on a Reddit post a while ago (via NVIDIA APP > Max Frame Rate).

I unfortunately get this gray flickering during gaming but I can get used to it. However, what I cannot stand is, when I tried using editing software (like Adobe Premiere Pro), the flickering was also present despite me having turned off GSync specifically for that app (via NVIDIA App). Is there something I am doing wrong? What can be done to completely eliminate flickering for non-game apps?

HagenKL
Member
HagenKL

Hey, the article talks about GSync with the Module. Is the Behaviour the same for GSync Compatible (aka Freesync monitors?)

wpDiscuz