How To Reduce Input Latency When Using Frame Generation - V-Sync vs RTSS

Join this channel to support a creator:
/ @mostly_positive_reviews
Have you ever wondered which method of limiting your frame rates provides the best experience? Today we'll be testing v-sync, or vertical sync against manually capping your frame rate by using an external 3rd party application, like Riva Tuner Statistics Server, included with MSI Afterburner.
We'll be testing with and without DLSS 3 Frame Generation in Cyberpunk 2077: Phantom Liberty, and Robocop: Rogue City, and then also test the differences between using a framerate cap and v-sync.
When using DLSS 3 Frame Generation it's not possible to enable V-sync (vsync) in game, so you have to use the Nvidia Control Panel to force v-sync on.
Also, using RTSS with the "async" option next to the framerate limiter causes very high input latency. In this video we also show you how to resolve that so you can still continue using RTSS as a frame rate limiter without increasing the input latency when using DLSS 3 Frame Generation.
System Specs:
Intel Core i5 14600KF @ Stock
Palit Dual Nvidia GeForce RTX 4070 Super @ Stock
Gigabyte Gaming X AX Z790 Motherboard
G-Skill 32GB DDR5 6400 Mt/s CL32 Memory
Corsair HX850i Power Supply
Windows 11 Pro
2TB PCIE Gen 4 Nvme Drive
Game Mode and ReBAR enabled
Dell 27" 1440p 165Hz IPS Monitor
Join this channel to support a creator:
/ @mostly_positive_reviews
Timestamps:
0:00 - Using NVCP to enable V-Sync
0:34 - How does Nvidia Reflex impact frame rates?
1:49 - Cyberpunk 2077 | V-sync on, DLSS FG Off
2:20 - Cyberpunk 2077 | RTSS FPS Cap On (async), DLSS FG Off
3:25 - Cyberpunk 2077 | V-sync on, DLSS FG On
3:50 - Cyberpunk 2077 | RTSS FPS Cap On (async), DLSS FG On
4:36 - How to Improve Input Latency by using Reflex in RTSS
4:51 - Cyberpunk 2077 | RTSS FPS Cap On (Reflex), DLSS FG On
5:22 - Robocop | V-sync on, DLSS FG On
6:01 - Robocop | RTSS FPS Cap On (async), DLSS FG On
8:02 - Robocop | RTSS FPS Cap On (Reflex), DLSS FG On

[@Mostly_Positive_Reviews]

Just want to say thanks to the people that made me aware of the Reflex setting in RTSS. Without you my old video would still be up and it would've give RTSS a bad name!

[@jmorgado4126]

Hi! Great video! SInce the making of this video, have you tested the latency with the in game FPS limiter instead of V-sync or RTSS? In many games it gives a lot less latency. It would also be great to see the initial amount of latenncy you were getting before you enabled V-sync or RTSS, to see if it increased od drecreased when enabling them. I would love to know your opinion. thank you

[@Mostly_Positive_Reviews]

Thanks! I have personally found that latency might be slightly better, but many games have frame time pacing issues when using the in-game limiter. RTSS / v-sync give an overall smoother experience. Not all games though, there are games that can perfectly cap the framerate but it depends on the game. Will remember to show the latency before in future, but it is lower as the framerate is higher without a cap in place.

[@bujaysedutan9328]

I would like to share my settings for low latency. 75hz 1080P Monitor - DLDSR 2.25 (1620P) CP2077 - FG On NVCP - Vsync Adaptive NVCP - Frame Cap 60 Avg Latency - 30-33ms With RTSS Cap + Reflex On, I'm getting frame spikes. Tried different frame cap combinations (NVCP + RTSS Reflex, etc) but these settings above helped me with the smoothness and image stability.

[@Mostly_Positive_Reviews]

Definitely going to test this, thanks! Getting 30ms Avg latency with FG on and a framerate cap at 60 is very low, and if I can replicate this I will definitely share this info, thanks 👍

[@Mostly_Positive_Reviews]

When using these settings I get 68-72ms. Only when I disable FG do I get 30-33ms with NVCP 60 fps cap and Adaptive v-sync. Render latency is sitting at 30ms, but PC Latency is more than double that. You sure you are talking about Avg PC Latency, as displayed in the video?

[@WSS_the_OG]

I'm curious how RTSS frame rate cap compares with Nvidia Control Panel frame rate limit in terms of latency, FG on and off. Thanks for this very interesting video!

[@Mostly_Positive_Reviews]

I've seen the NVCP fps cap overshoot some times, meaning if set to 120 fps it will sometimes jump to 123 and come back down. It can happen with RTSS as well, but in my personal experience it happens to a much lesser degree. I will check if it is reflex aware (I think it should be) and let you know 👍

[@justfun5479]

Interesting video. I don't plan to ever limit the FPS, cuz the higher the input lag, the more I'm pissed. I'm wonder if G-Sync and Free Sync are superior to in-game V-Sync.

[@Mostly_Positive_Reviews]

The only reason I use v-sync is to keep the frame rate below my monitor's max refresh rate, otherwise in some games it can exceed it with FG enabled, and I get tearing, even with freesync or g-sync enabled, as neither of those limit the max framerate.

[@mustafademir1165]

When I limit the FPS to 72 via RTSS, lossless scaling does not work. What do you think could be the solution to this? (When I limit the FPS via the Nvidia control panel, there is no problem, this problem only with RTSS)

[@Mostly_Positive_Reviews]

I am assuming you are trying to cap the framerate to 72 so that with frame gen you'll get 144 fps? I'm not sure if RTSS is aware of lossless scaling, but almost all games now are DLSS FG and FSR FG aware, so if you want 144fps you cap it to 144fps. What happens if you cap RTSS to 144 fps? Does lossless scaling still not work?

[@supernice_auto]

nice video- what software is being used to populate that 'average pc latency' metric in the upper right?

[@Mostly_Positive_Reviews]

Thanks! I used the Nvidia App, which has an overlay with these metrics 👍

[@Lennox032]

Always undervolt and set a frame rate cap, reduce heat and power, less frame rate dips.

[@paradoxic1888]

I've got a 4070. Can someone explain why my latency if in the 90s no matter what settings I try?

[@Mostly_Positive_Reviews]

Do you use v-sync or a framerate cap? What is your framerate when you see 90ms? Also, which game?

[@paradoxic1888]

Here are my settings: Res - 2560 x 1440 PT - On DLSS - Balanced Graphics Settings - Custom but mostly high settings Frame cap is turned on in Nvidia Control Panel FPS - 44 (frame gen off) Lat - +- 75 (frame gen off) With frame gen on latency hangs around 120 with frame gen on. I capped it to 60fps which would otherwise jump to 75 if I don't have it capped. Changing to Ray Tracing, 1080p etc. doesn't really make a difference. Is it perhaps another hardware like RAM or CPU that can affect it?

[@Mostly_Positive_Reviews]

44fps as a base framerate is too low for frame gen to work well. Nvidia and AMD both recommend 60 fps, but I personally prefer 90. Unfortunately that means that path tracing is out of the question for most GPUs, unless you can get used to the input latency.

[@paradoxic1888]

Update: The issue was my RAM. I removed the module that runs at lower MHZ and do not support XMP. I then enabled the feature and set the MHZ manually in the BIOS. The latency went down a lot. Unfortunately it's not top of the line RAM, but it makes a huge difference.

[@EndGxme]

@Mostly_Positive_Reviews I don't know if I'm just being dumb here, but I don't understand why you would want to use a frame rate limiter when Relex already does it for you.

[@kimjongpoontv69]

reflex only limits your frames if you have vsync engaged in game or forced in control panel, i presume hes using the RTSS reflex option wihtout vsync engaged in either one.

[@Mostly_Positive_Reviews]

Yeah, this. Using Reflex with v-sync limits your framerate to around 3% below your monitor's refresh rate. Reflex on its own doesnt limit the framerate. So the tests with v-sync on has reflex enabled as well because frame generation automatically enables Reflex. I then used that same output framerate to limit to using RTSS to keep the max fps equal between the tests.

[@Mostly_Positive_Reviews]

Answered below. Reflex on its own does not limit your max framerate. It only limits it to around 3% below your monitor's max refresh rate when using v-sync + reflex.

[@EndGxme]

@@Mostly_Positive_Reviews I understand that you can limit your frame rate to the same as Reflex with RTSS in (Reflex mode) without the need to use Vsync but from my testing at least if I even get within 10 frames of my Max refresh rate I can get tearing with without Vsync so I'm not sure what the point is using an external cap without Vsync that's all

[@Mostly_Positive_Reviews]

@@EndGxme Do you have g-sync enabled? Typically you wouldnt see tearing when within the g-sync range, so it's maybe possible you are outside of that range? But yeah, as I said in the video, I personally just stick with v-sync enabled as it has given me the best overall results. Doesnt increase latency, no tearing, consistent frame pacing etc.

[@Jakiyyyyy]

Why I don't have the Reflex option inside the RTSS? Does it per game basis thing? 🤷🏻‍♀️

[@Mostly_Positive_Reviews]

It's not on a per game basis as I can select it even from the desktop. What GPU do you have? Also, which version of RTSS do you have installed? I currently use 7.3.6

[@Retr-lk5ns]

@@Mostly_Positive_Reviews me neither I only have async, front edge and back edge. I have an RTX 4060

[@jmorgado4126]

@@Retr-lk5ns and @Jakiyyyyy I didnt have the option on version 7.3.4 of rivatuner, and as soon as I updated to 7.3.6 I got it on the menu.

[@supernice_auto]

also is image scaling (TAA), which is the option available in halo infinite for example, the same as 'frame generation' in this context?

[@Mostly_Positive_Reviews]

TAA stands for Temporal Anti Aliasing, and the scaling portion of it is called TSR, for Temporal Super Resolution. TAA scaling is an upscaler which will render the game internally at a lower resolution and then upscale it to your monitor's resolution. These solutions from Nvidia. AMD, and Intel are called DLSS SR, FSR, and XeSS respectively, and they dont generate any frames, they only upscale. The frame generation portion is called DLSS Frame Generation and FSR Frame Generation. These are currently the only two frame generation techniques built into some games. AMD has a solution called AFMF that can be enabled at a driver level to generate additional frames in any game, but it has a few more drawbacks.

[@supernice_auto]

@@Mostly_Positive_Reviews thank you for the clarification here- im trying to determine if halo infinite's implementation of resolution scaling would introduce input latency while allowing for higher fps- my understanding is that yes but the higher fps might offset the input latency introduced by resolution scaling processing.

[@Mostly_Positive_Reviews]

@@supernice_auto Ah okay. Resolution scaling does have a slight performance overhead, meaning that if you upscale from 1080p to 4K you will get lower performance than at 1080p native, but much better than at 4K native. But It doesnt introduce additional input latency, it actually is very much in line with your actual framerate. So it would decrease your input latency. Not as much as if lowering the native resolution, but still much better than running at your monitor's native resolution.

[@supernice_auto]

@@Mostly_Positive_Reviews sorry i meant scaling up so running game at a lower resolution then scaling up to native 1080p res. outside of getting a monitor with built in nvidia reflex analyizer how can you test for input latency? is capframex a reliable approach (looking at frametimes for example)

[@Mostly_Positive_Reviews]

Frametimes wouldnt indicate latency unfortunately. It only shows you how long it takes for a frame to be rendered. Using GeForce Experience you can check the Average PC latency, or using the Nvidia App. CapFrameX does have App Latency but to be honest I am not 100% sure exactly what that indicates.

[@MARKELL00F]

Awesome work bro 👏 please how to get Average pc overlay ?

[@Mostly_Positive_Reviews]

I used Nvidia App. You can just install it, and to show these metrics you press Alt+R in-game 👍