Kernel timer latency?

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OnlyForThemMoment
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Joined: 22 Sep 2022, 13:08

Kernel timer latency?

Post by OnlyForThemMoment » 22 Sep 2022, 13:22

Hey there! I'm not usually a forum poster, but as I've been trying to scout the internet for a possible solution to my DPC latency issues I figured why not ask the people here directly.

For a long time my PC has been what you describe as "Heavy" "Desynced" "Audio stuttery" etc.. you know, the usual jazz you find around "input lag" threads in general. And no, this is not an EMI thread. As I know all EMI related stuff has their own thread for it, nor is it an issue for me since I've had plenty good PCs before this one, all in the same place.

This is however the first time I heard about "DPC latency" and got curious to wether I might have it or not.. so I checked.. All green. Great. However, if you choose "Options" under "Tools" there's an option to click "Kernel timer latency" and oh boy... Red all cross the screen haha.

So, I'm asking if this might just be a "normal" thing were you to check it out yourselves using the same option in Latencymon.
And if not, what in the world can I do about this? :D

Thank you!
dpc.png
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Ragerlis
Posts: 32
Joined: 06 Sep 2020, 09:40

Re: Kernel timer latency?

Post by Ragerlis » 23 Sep 2022, 13:18

OnlyForThemMoment wrote:
22 Sep 2022, 13:22
Hey there! I'm not usually a forum poster, but as I've been trying to scout the internet for a possible solution to my DPC latency issues I figured why not ask the people here directly.

For a long time my PC has been what you describe as "Heavy" "Desynced" "Audio stuttery" etc.. you know, the usual jazz you find around "input lag" threads in general. And no, this is not an EMI thread. As I know all EMI related stuff has their own thread for it, nor is it an issue for me since I've had plenty good PCs before this one, all in the same place.

This is however the first time I heard about "DPC latency" and got curious to wether I might have it or not.. so I checked.. All green. Great. However, if you choose "Options" under "Tools" there's an option to click "Kernel timer latency" and oh boy... Red all cross the screen haha.

So, I'm asking if this might just be a "normal" thing were you to check it out yourselves using the same option in Latencymon.
And if not, what in the world can I do about this? :D

Thank you!dpc.png
This is the resolution timer pretty much(the reason i mean), as you can see, its set to 20ms.

Opening a video/game/general multimedia should drop the value to 1ms(1000us), you can drop it to 500 forcing resolution timer to the lowest possible with certain apps/commands.

Yours is set to 20ms because the computer is likely on idle.

Can or cannot be a problem, depends how it reacts when needed, if you are seeing this with a game opened, yes, there is a problem, if its just idle on desktop with nothing running, its normal.

OnlyForThemMoment
Posts: 3
Joined: 22 Sep 2022, 13:08

Re: Kernel timer latency?

Post by OnlyForThemMoment » 23 Sep 2022, 17:31

Ragerlis wrote:
23 Sep 2022, 13:18
OnlyForThemMoment wrote:
22 Sep 2022, 13:22
Hey there! I'm not usually a forum poster, but as I've been trying to scout the internet for a possible solution to my DPC latency issues I figured why not ask the people here directly.

For a long time my PC has been what you describe as "Heavy" "Desynced" "Audio stuttery" etc.. you know, the usual jazz you find around "input lag" threads in general. And no, this is not an EMI thread. As I know all EMI related stuff has their own thread for it, nor is it an issue for me since I've had plenty good PCs before this one, all in the same place.

This is however the first time I heard about "DPC latency" and got curious to wether I might have it or not.. so I checked.. All green. Great. However, if you choose "Options" under "Tools" there's an option to click "Kernel timer latency" and oh boy... Red all cross the screen haha.

So, I'm asking if this might just be a "normal" thing were you to check it out yourselves using the same option in Latencymon.
And if not, what in the world can I do about this? :D

Thank you!dpc.png
This is the resolution timer pretty much(the reason i mean), as you can see, its set to 20ms.

Opening a video/game/general multimedia should drop the value to 1ms(1000us), you can drop it to 500 forcing resolution timer to the lowest possible with certain apps/commands.

Yours is set to 20ms because the computer is likely on idle.

Can or cannot be a problem, depends how it reacts when needed, if you are seeing this with a game opened, yes, there is a problem, if its just idle on desktop with nothing running, its normal.
That's very interesting! Thank you for your help in clearing that up for me. And yes, it seems as it's not changing during gaming either. I have both tried starting the test before hand & while in-game, all with the same results. If I understand correctly this would imply something is faulty within the OS itself? I'm open for suggestions if anybody has any idea to why it's not lowering during use!

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RealNC
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Re: Kernel timer latency?

Post by RealNC » 24 Sep 2022, 04:41

OnlyForThemMoment wrote:
23 Sep 2022, 17:31
That's very interesting! Thank you for your help in clearing that up for me. And yes, it seems as it's not changing during gaming either.
Try https://github.com/tebjan/TimerTool
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Vocaleyes
Posts: 287
Joined: 09 Nov 2021, 18:10

Re: Kernel timer latency?

Post by Vocaleyes » 24 Sep 2022, 04:53

Thought I'd give it a go too. Same circumstances with it not adjusting during gaming either, thought I'd share just in case!
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kernel timer latency.jpg
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Last edited by Vocaleyes on 24 Sep 2022, 05:42, edited 1 time in total.

Vocaleyes
Posts: 287
Joined: 09 Nov 2021, 18:10

Re: Kernel timer latency?

Post by Vocaleyes » 24 Sep 2022, 04:55

RealNC wrote:
24 Sep 2022, 04:41
OnlyForThemMoment wrote:
23 Sep 2022, 17:31
That's very interesting! Thank you for your help in clearing that up for me. And yes, it seems as it's not changing during gaming either.
Try https://github.com/tebjan/TimerTool
I'm currently using ISLC to force timer to 0.50, would this app do a better job of it?

Vocaleyes
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Joined: 09 Nov 2021, 18:10

Re: Kernel timer latency?

Post by Vocaleyes » 24 Sep 2022, 05:51

Here's another sh with timer tool v3 running.
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kernel timer latency with timer tool.jpg
kernel timer latency with timer tool.jpg (204.33 KiB) Viewed 6175 times

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RealNC
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Re: Kernel timer latency?

Post by RealNC » 24 Sep 2022, 06:33

Vocaleyes wrote:
24 Sep 2022, 04:55
I'm currently using ISLC to force timer to 0.50, would this app do a better job of it?
I believe they do the exact same thing, so it shouldn't matter.
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Vocaleyes
Posts: 287
Joined: 09 Nov 2021, 18:10

Re: Kernel timer latency?

Post by Vocaleyes » 24 Sep 2022, 07:06

Ok sweet, seems kernel timer latency is unaffected regardless of the load/ combination of settings.

Tried apex and modern warfare both in fse and windowed just to see if any impact, but the timer remains in this range from boot. Could this be what’s affecting mouse input response and some performance issues in general with regard to gaming?

Would there be any workaround available currently to decrease kernel timer latency?

Vocaleyes
Posts: 287
Joined: 09 Nov 2021, 18:10

Re: Kernel timer latency?

Post by Vocaleyes » 24 Sep 2022, 12:47

Here it is after being left running for 4 hours, as you can see the current value remains unchanged. Also there is now DPC latency from ntsokrnl.
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kernel latency after 4 hours.jpg
kernel latency after 4 hours.jpg (251.57 KiB) Viewed 6072 times

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