Should you be worried about 1, 5, or 10 ms of input lag? Use Latency Split Test (LST) and find out!

Everything about latency. This section is mainly user/consumer discussion. (Peer-reviewed scientific discussion should go in Laboratory section). Tips, 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.
User avatar
jorimt
Posts: 2641
Joined: 04 Nov 2016, 10:44
Location: USA

Re: Should you be worried about 1, 5, or 10 ms of input lag? Use Latency Split Test (LST) and find out!

Post by jorimt » 01 Oct 2023, 10:15

Rali wrote:
01 Oct 2023, 03:42
if I do decid to cap it do I turn of reflex? Or leave it on with the fps cap?
Reflex is the automatic version of a manually set cap, so you don't need both. I.E. only use a manual cap to prevent max GPU usage if Reflex isn't available.
(jorimt: /jor-uhm-tee/)
Author: Blur Busters "G-SYNC 101" Series

Displays: ASUS PG27AQN, LG 48C4 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) Keyboard: Wooting 60HE Mouse: Razer Viper Mini SE Sound: Creative Sound Blaster Katana V2 VR: Beyond 2, Quest 3, Reverb G2, Index Consoles: Dreamcast, PS2, PS3, PS5, Switch 2, Wii, Xbox, Analogue Pocket + Dock Scaler: RetroTINK 4k

mago
Posts: 102
Joined: 05 Sep 2022, 11:28

Re: Should you be worried about 1, 5, or 10 ms of input lag? Use Latency Split Test (LST) and find out!

Post by mago » 03 Oct 2023, 04:50

TV OLED
really hard to notice the diff, can be the hz can be the stutters

Viper 8k @ 1600DPI / 8Khz
1440p @ 120HZ

mb adding random input lag with stddev like in games would be same what beneficial
Attachments
120hz-OLED.jpg
120hz-OLED.jpg (25.89 KiB) Viewed 3702 times
Ⓢк𝕀lŁ เ𝓢 ᵗⒺм𝕡σr𝐀𝐑Ⓨ, lά𝔾 I𝐬 F𝔬ʳ𝔢𝓿ᗴ𝔯

MatrixQW
Posts: 311
Joined: 07 Jan 2019, 10:01

Re: Should you be worried about 1, 5, or 10 ms of input lag? Use Latency Split Test (LST) and find out!

Post by MatrixQW » 01 Apr 2026, 08:29

I never mentioned that to get steady 1000 fps, excluding core 0 and all HT/SMT cores, is necessary.
I have an I7-4790K. Don't know how affinity will be with Intel CPUs with P and E cores.
This happens because core 0 gets a very high load and GPU interrupts (ISR/DPC) cause the drop in performance.

Try this CPU Affinity Mask Calculator. In the shortcut properties I used affinity:
- Start in: "D:\Apps\Latency Split Test\WindowsNoEditor\LatencySplitTest\Binaries\Win64"
- Target: %ComSpec% /C start "" /affinity 54 "LatencySplitTest-Win64-Shipping.exe"

Probably no one cares about this test anymore, but if someone wants to try, the affinity should help.

User avatar
Espionage724
Posts: 32
Joined: 13 Jul 2022, 15:45

Re: Should you be worried about 1, 5, or 10 ms of input lag? Use Latency Split Test (LST) and find out!

Post by Espionage724 » 01 Apr 2026, 14:52

Discorz wrote:
28 Jan 2022, 16:33
Gamers want the lowest latency possible, but how much does this actually matter? Can you even feel the difference between 5 or 10 or 20 milliseconds of lag? Aperture Grille's Latency Split Test (LST) is a program designed to help you determine your personal sensitivity to lag.
Human perception can vary; I want my computer having as little-to-no latency as possible consistently 8-)

Interesting test though :)

User avatar
RealNC
Site Admin
Posts: 4589
Joined: 24 Dec 2013, 18:32
Contact:

Re: Should you be worried about 1, 5, or 10 ms of input lag? Use Latency Split Test (LST) and find out!

Post by RealNC » 01 Apr 2026, 16:13

Btw, the most important latency test is mouse look (meaning when the camera/viewport in a game is directly tied to mouse movement.)

IMO, any testing tool that doesn't test that explicitly is not that useful. Latency on mouse clicks is not as important. Mouse look is. Mouse clicks (or gamepad button presses) feel about the same to me at 20ms and 40ms. But mouse look? Even a 10ms increase is immediately noticeable to me, as I can feel the camera being slightly behind my hand movement.
SteamGitHubStack Overflow
The views and opinions expressed in my posts are my own and do not necessarily reflect the official policy or position of Blur Busters.

nickchraj
Posts: 24
Joined: 29 Mar 2026, 11:37

Re: Should you be worried about 1, 5, or 10 ms of input lag? Use Latency Split Test (LST) and find out!

Post by nickchraj » 01 Apr 2026, 16:39

Here are my results, pretty sure i can do better if i focus enough. also this is on 60hz
Attachments
Untitled.png
Untitled.png (68.86 KiB) Viewed 936 times

mago
Posts: 102
Joined: 05 Sep 2022, 11:28

Re: Should you be worried about 1, 5, or 10 ms of input lag? Use Latency Split Test (LST) and find out!

Post by mago » 02 Apr 2026, 17:50

mb with 700hz, people / pro players can do 0.75ms
will prove that every ms count :)
Ⓢк𝕀lŁ เ𝓢 ᵗⒺм𝕡σr𝐀𝐑Ⓨ, lά𝔾 I𝐬 F𝔬ʳ𝔢𝓿ᗴ𝔯

netborg
Posts: 38
Joined: 04 Apr 2025, 06:38

Re: Should you be worried about 1, 5, or 10 ms of input lag? Use Latency Split Test (LST) and find out!

Post by netborg » 06 Apr 2026, 11:41

This test is pretty bad and in no way can represent what humans latency perception threshold is.

The reason is pretty simple: It only updates a tiny fraction of what you're seeing, you're burning ~100 lines onto the retina (sample and hold blur) and now you expect that adding one line every frame is somehow related to a real game which updates the whole screen every frame. That's clearly not working out.

Post Reply