Reduce Input Delay (Mouse & Keyboard Buffer Size)

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.
andrelip
Posts: 160
Joined: 21 Mar 2014, 17:50

Re: Reduce Input Delay (Mouse & Keyboard Buffer Size)

Post by andrelip » 26 Feb 2021, 17:15

Negative sensitivity is an exciting subject.

Some considerations:

1: If FPS and Hz are not harmonically updated; it will not feel like 1:1

2: Do the game use an async thread to read mouse inputs?

3: The way the CPU is being limited may affect the IO.

3.1 Is the CPU 100% busy?
3.2 Do it have an FPS capping? How the game implements the sleep() function?
3.3 Is there any sleep() happening in the present hooks (RTSS)?
3.4 Is the CPU being blocked by Max-Rendered Queue of 1 while waiting for the GPU.
3.5 Do V-Sync is limiting the game?

4: Is there a race condition for mouse interrupt processing?
4.1 Is the system buffering and processing it in batches?

5: Is the processor going to deeper C-States?

These are just some things that can drop or jitter events and generate the negative acceleration feeling even with perfect hardware.

empleat
Posts: 149
Joined: 28 Feb 2020, 21:06

Re: Reduce Input Delay (Mouse & Keyboard Buffer Size)

Post by empleat » 26 Feb 2021, 19:33

andrelip wrote:
26 Feb 2021, 17:15
Negative sensitivity is an exciting subject.
I was talking in the middle about negative acceleration in general, since I touched negative things about mouse movement.

I do not feel like I have strong negative acceleration currently. I do not feel acceleration, it moves pretty much about same distance. But it is more like dynamic lag. I did not even know, that you can cause negative acceleration by all those things you have mentioned. But there are games that have hardcoded negative acceleration into them, e.g. Arma 3, Horizons Zero New Dawn!

1. I use G-SYNC with fps capped at 140, it doesn't even overshoot, constant stable.
2. Game in question is BF4, or BF1, no idea what it uses. Also nothing I can do with that.

3.1 Probably not 100% busy, but BF is CPU demanding. It is 9600kf, so it should be more then fine for both games! I have also enabled all CPU cores, as they are not enabled by default.
3.2 Yep capped fps to 140, I read it is best to cap fps in game engine for lower input lag, but riva tuner is also a good option , maybe I can try it too!
3.3 Not sure what does that mean, I didn't use RTSS much, except for fps overlay. Nor I use it currently actively (also they ban in BF for reshade etc. not sure if you talk about hooking application to the game for some measurement perhaps) - I don't want to do that!
3.4 BF uses render queue -1, not sure how it works exactly, as my understanding is: you need at least 1 pre-rendered frame from CPU so GPU has to do work. Maybe something as Nvidia Ultra Low Latency Mode, just implemented in the game to reduce render queue. But it is set -1 on default and feels best, input lag is significant on 1!
3.5 no vsync

4. Probably not, I have DPC latency average 100us, lately I saw some spikes for ntoskrnl.exe to 200 us (interrupt to user process latency) which is still ok, wddf1000.sys has like 33us maximum execution time, tested outside game 30 minutes!
4.1 Don't know how to monitor buffering, I recently tried this tweak and reducing it makes mouse more inconsistent, but lowers input lag. However I felt same, before using this!

5. I use Ultimate Power Profile + disable idle saver, there is no C1 time, or idle time in perfmon. C states disabled in BIOS, only enabled Intel Speed Shift and turbo.
Also no overheating, thermal throttling, no oc.

mossfalt
Posts: 37
Joined: 23 Nov 2020, 08:43

Re: Reduce Input Delay (Mouse & Keyboard Buffer Size)

Post by mossfalt » 27 Feb 2021, 17:47

howiec wrote:
03 Feb 2021, 18:46
Oh and btw, MouseDataQueueSize does make a difference..
what kind of difference are you experiencing :idea:

howiec
Posts: 183
Joined: 17 Jun 2014, 15:36

Re: Reduce Input Delay (Mouse & Keyboard Buffer Size)

Post by howiec » 28 Feb 2021, 00:25

mossfalt wrote:
27 Feb 2021, 17:47
howiec wrote:
03 Feb 2021, 18:46
Oh and btw, MouseDataQueueSize does make a difference..
what kind of difference are you experiencing :idea:
What you'd expect due to a smaller buffer. Feels more responsive / accurate and precise. Too low of a value can obviously lead to issues though.

mossfalt
Posts: 37
Joined: 23 Nov 2020, 08:43

Re: Reduce Input Delay (Mouse & Keyboard Buffer Size)

Post by mossfalt » 28 Feb 2021, 17:56

howiec wrote:
28 Feb 2021, 00:25
mossfalt wrote:
27 Feb 2021, 17:47
howiec wrote:
03 Feb 2021, 18:46
Oh and btw, MouseDataQueueSize does make a difference..
what kind of difference are you experiencing :idea:
What you'd expect due to a smaller buffer. Feels more responsive / accurate and precise. Too low of a value can obviously lead to issues though.
Ok what do you set it to? I think I wan't to try this when I get time.
Last edited by mossfalt on 01 Mar 2021, 06:19, edited 1 time in total.

User avatar
BTRY B 529th FA BN
Posts: 523
Joined: 18 Dec 2013, 13:28

Re: Reduce Input Delay (Mouse & Keyboard Buffer Size)

Post by BTRY B 529th FA BN » 01 Mar 2021, 00:28

My 'KeyboardDataQueueSize' defaults to 100 decimal. I changed mine to 50 decimal. Noticed a reduction in input delay.

Created the reg key 'Parameters' for MouClass. Rebooted, then created d-word 32bit 'MouseDataQueueSize' and set the same decimal to 50. Not sure if it was necessary but I may delete it and see if there's any difference. I know the keyboard edit made a difference.

empleat
Posts: 149
Joined: 28 Feb 2020, 21:06

Re: Reduce Input Delay (Mouse & Keyboard Buffer Size)

Post by empleat » 01 Mar 2021, 13:03

BTRY B 529th FA BN wrote:
01 Mar 2021, 00:28
My 'KeyboardDataQueueSize' defaults to 100 decimal. I changed mine to 50 decimal. Noticed a reduction in input delay.

Created the reg key 'Parameters' for MouClass. Rebooted, then created d-word 32bit 'MouseDataQueueSize' and set the same decimal to 50. Not sure if it was necessary but I may delete it and see if there's any difference. I know the keyboard edit made a difference.
50 is too high.

This guy recommends starting slowly from like 50. And recommends not to go below 20 and used 16, says: if you have good system. https://www.youtube.com/watch?v=FkVQm-hyL28

I use 20 currently, but it depends on your hw, polling etc. You will have to find balance between consistency and input lag!

Also in control panel keyboard, you can try set repeat delay to short. This makes input starting to repeat itself faster, when you press and hold button, default there is like 250ms delay.

Also there is app: FilterKeysSetter. Which using filter keys lets you set custom option. However, I don't know, if this is best to change for all games. I used that for RTS to start queue units faster, but in fps, it can be hard to stop on place, when you need to fire - for prevision.

chenifa
Posts: 51
Joined: 31 Aug 2019, 18:07

Re: Reduce Input Delay (Mouse & Keyboard Buffer Size)

Post by chenifa » 02 Mar 2021, 07:42

empleat wrote:
01 Mar 2021, 13:03
Also in control panel keyboard, you can try set repeat delay to short. This makes input starting to repeat itself faster, when you press and hold button, default there is like 250ms delay.
In what game would that make a difference? Not a single fps game I know hast input repeat delay....

empleat
Posts: 149
Joined: 28 Feb 2020, 21:06

Re: Reduce Input Delay (Mouse & Keyboard Buffer Size)

Post by empleat » 02 Mar 2021, 20:53

chenifa wrote:
02 Mar 2021, 07:42
empleat wrote:
01 Mar 2021, 13:03
Also in control panel keyboard, you can try set repeat delay to short. This makes input starting to repeat itself faster, when you press and hold button, default there is like 250ms delay.
In what game would that make a difference? Not a single fps game I know hast input repeat delay....
You may not understand what this does exactly. This is delay, before pressed key starts to repeat itself. It allows you to start moving faster, since time you press W key. Once you are moving, it does nothing however. Also as I said: I used this to queue units faster in a RTS. In FPS you may want to use default windows setting, because it is harder to stop at place then - for shot accuracy. But it may useful on game you are playing and comes as a personal preference.

chenifa
Posts: 51
Joined: 31 Aug 2019, 18:07

Re: Reduce Input Delay (Mouse & Keyboard Buffer Size)

Post by chenifa » 03 Mar 2021, 07:44

This setting only applies in windows, not in any fps.....try and turn the delay all the way up, it will make no difference ingame.

Post Reply