Low lag Vsync with multiples of Hz

Everything about latency. Tips, testing methods, mouse lag, display lag, game engine lag, network lag, whole input lag chain, VSYNC OFF vs VSYNC ON, and more! Input Lag Articles on Blur Busters.
Post Reply
yamaci1775
Posts: 14
Joined: 27 Jan 2019, 02:29

Low lag Vsync with multiples of Hz

Post by yamaci1775 » 28 Nov 2022, 17:32

Hello, https://blurbusters.com/howto-low-lag-vsync-on/ With this guide, you can achieve low lag input lag with -0.01 of the refresh rate. How about 1/2 1/3 and so on multiples? For example my screen refreshes at 119.982 after 40+ seconds of stability with refresh rate test. If I want to use 1/3 Vsync to lock a game to 40 FPS, what should be my framecap? 39.990? What would be the ideal approach in such a situation?

User avatar
CorvusCorax
Posts: 40
Joined: 14 Nov 2020, 06:22

Re: Low lag Vsync with multiples of Hz

Post by CorvusCorax » 02 Dec 2022, 06:30

Hi, I have similar question on this forum and sadly nobody can answer me. But I made some progress to testing it and it looks like you can't divide your screen refresh rate for no tearing and low input lag.

For example my screen refresh rate is 239.713Hz and minimal fps in game I want to run is for example 100fps. So I divided 239.713 / 3 and set framelimit in RTSS for this value and yes, input lag is low but screen tearing is still visible.

So I downloaded Nvidia Pendelum Demo and set the framerate to the moving line to achieve the most non-visible tearing below 100fps. It turned out that for my 239.713Hz monitor the best option for framelimit is 93fps.

It follows that it is better to test it "by eye" than to believe the calculations.

But there is another question. What V-sync does if you turn on framelimit for above example for 93fps on 240Hz display panel. Nobody can answer this question :D

User avatar
jorimt
Posts: 2481
Joined: 04 Nov 2016, 10:44
Location: USA

Re: Low lag Vsync with multiples of Hz

Post by jorimt » 02 Dec 2022, 10:57

yamaci1775 wrote:
28 Nov 2022, 17:32
Hello, https://blurbusters.com/howto-low-lag-vsync-on/ With this guide, you can achieve low lag input lag with -0.01 of the refresh rate. How about 1/2 1/3 and so on multiples? For example my screen refreshes at 119.982 after 40+ seconds of stability with refresh rate test. If I want to use 1/3 Vsync to lock a game to 40 FPS, what should be my framecap? 39.990? What would be the ideal approach in such a situation?
To my knowledge, the 1/2, 1/3, and 1/4 Refresh Rate V-SYNC settings available in Nvidia Inspector basically apply V-SYNC at a division of the current max refresh rate, hence 1/4 Refresh Rate V-SYNC at 240Hz is an effective 60HZ V-SYNC, which means, at 240Hz, each frame is repeated 4 times, so frame 1 = 1, 1, 1, 1, frame 2 = 2, 2, 2, 2, and so on.

It's basically identical to standard 60+ FPS V-SYNC at 60Hz, just at a 240Hz scanout, hence it's just evenly repeating each frame 4 times in a row within the same period, resulting in standard V-SYNC behavior, latency and all.

As for low lag V-SYNC methods, I haven't tried them with the divisional V-SYNC options, so can't speak on that directly.
(jorimt: /jor-uhm-tee/)
Author: Blur Busters "G-SYNC 101" Series

Displays: ASUS PG27AQN, LG 48CX VR: Beyond, Quest 3, Reverb G2, Index OS: Windows 11 Pro Case: Fractal Design Torrent PSU: Seasonic PRIME TX-1000 MB: ASUS Z790 Hero CPU: Intel i9-13900k w/Noctua NH-U12A GPU: GIGABYTE RTX 4090 GAMING OC RAM: 32GB G.SKILL Trident Z5 DDR5 6400MHz CL32 SSDs: 2TB WD_BLACK SN850 (OS), 4TB WD_BLACK SN850X (Games) Keyboards: Wooting 60HE, Logitech G915 TKL Mice: Razer Viper Mini SE, Razer Viper 8kHz Sound: Creative Sound Blaster Katana V2 (speakers/amp/DAC), AFUL Performer 8 (IEMs)

User avatar
jorimt
Posts: 2481
Joined: 04 Nov 2016, 10:44
Location: USA

Re: Low lag Vsync with multiples of Hz

Post by jorimt » 02 Dec 2022, 11:01

CorvusCorax wrote:
02 Dec 2022, 06:30
For example my screen refresh rate is 239.713Hz and minimal fps in game I want to run is for example 100fps. So I divided 239.713 / 3 and set framelimit in RTSS for this value and yes, input lag is low but screen tearing is still visible.
You can't remove tearing without a syncing method, no matter what your framerate/refresh rate ratio is set to.

As for input lag, if V-SYNC is off, input lag at the display-level is already the lowest possible, regardless of your current framerate/refresh rate ratio. Input lag only becomes a factor in this respect when you enable a syncing method.

If, however, you're saying you're experiencing tearing with a syncing method enabled, then there's simply something wrong with your configuration, since the majority of syncing methods can't tear if set up properly.
(jorimt: /jor-uhm-tee/)
Author: Blur Busters "G-SYNC 101" Series

Displays: ASUS PG27AQN, LG 48CX VR: Beyond, Quest 3, Reverb G2, Index OS: Windows 11 Pro Case: Fractal Design Torrent PSU: Seasonic PRIME TX-1000 MB: ASUS Z790 Hero CPU: Intel i9-13900k w/Noctua NH-U12A GPU: GIGABYTE RTX 4090 GAMING OC RAM: 32GB G.SKILL Trident Z5 DDR5 6400MHz CL32 SSDs: 2TB WD_BLACK SN850 (OS), 4TB WD_BLACK SN850X (Games) Keyboards: Wooting 60HE, Logitech G915 TKL Mice: Razer Viper Mini SE, Razer Viper 8kHz Sound: Creative Sound Blaster Katana V2 (speakers/amp/DAC), AFUL Performer 8 (IEMs)

User avatar
CorvusCorax
Posts: 40
Joined: 14 Nov 2020, 06:22

Re: Low lag Vsync with multiples of Hz

Post by CorvusCorax » 03 Dec 2022, 08:42

jorimt wrote:
02 Dec 2022, 11:01
CorvusCorax wrote:
02 Dec 2022, 06:30
For example my screen refresh rate is 239.713Hz and minimal fps in game I want to run is for example 100fps. So I divided 239.713 / 3 and set framelimit in RTSS for this value and yes, input lag is low but screen tearing is still visible.
You can't remove tearing without a syncing method, no matter what your framerate/refresh rate ratio is set to.

As for input lag, if V-SYNC is off, input lag at the display-level is already the lowest possible, regardless of your current framerate/refresh rate ratio. Input lag only becomes a factor in this respect when you enable a syncing method.

If, however, you're saying you're experiencing tearing with a syncing method enabled, then there's simply something wrong with your configuration, since the majority of syncing methods can't tear if set up properly.
I know that I can't eliminate tearing without sync, but as I wrote above you can make it less visible. For my case it is a 93fps for fixed 240Hz display panel without V-Sync. No idea why 93fps works BTW ;)

But... I started doing some experiments with above settings and I eventually turned V-Sync on in nvcp (with framelimit in RTSS set at 93fps) on fixed 240Hz. It turned out that it works too, I have constant 93fps, no tearing, smooth frametimes on fixed 240Hz display panel and I don't feel any difference in input lag. I wonder how this works, why V-Sync behave different with framelimit. Any ideas?

User avatar
jorimt
Posts: 2481
Joined: 04 Nov 2016, 10:44
Location: USA

Re: Low lag Vsync with multiples of Hz

Post by jorimt » 03 Dec 2022, 12:03

CorvusCorax wrote:
03 Dec 2022, 08:42
I'm replying in your existing thread that is more on topic here:
viewtopic.php?f=10&t=10700&start=10#p87438
(jorimt: /jor-uhm-tee/)
Author: Blur Busters "G-SYNC 101" Series

Displays: ASUS PG27AQN, LG 48CX VR: Beyond, Quest 3, Reverb G2, Index OS: Windows 11 Pro Case: Fractal Design Torrent PSU: Seasonic PRIME TX-1000 MB: ASUS Z790 Hero CPU: Intel i9-13900k w/Noctua NH-U12A GPU: GIGABYTE RTX 4090 GAMING OC RAM: 32GB G.SKILL Trident Z5 DDR5 6400MHz CL32 SSDs: 2TB WD_BLACK SN850 (OS), 4TB WD_BLACK SN850X (Games) Keyboards: Wooting 60HE, Logitech G915 TKL Mice: Razer Viper Mini SE, Razer Viper 8kHz Sound: Creative Sound Blaster Katana V2 (speakers/amp/DAC), AFUL Performer 8 (IEMs)

Post Reply