# Is it possible to solve ACPI.sys DPC latency issue on laptop for music production?



## Charles Dan (Apr 22, 2021)

Hi, my CPU will have numerous massive spike to the max most of the time in my DAW when I plug in to charge my laptop and this caused a lot (almost all the time) audio dropouts and pops.

After intense research, with the help of LatencyMon, its the ACPI.sys driver that is causing the issue.
From what I know, ACPI.sys is related to power management/battery. It will use up some CPU cores when you are charging it.

Screw all the "Disable turbo mode", "turn on max performance" and all those general solutions.....it all doesn't work....


1.) - So I stumbled upon a way, and it is to disable the ACPI.sys, but this will cause the laptop to not charge at all. (Why the heck would you do that if your battery is running out, it doesn't make any sense LOL)

2.) - There is another option which is to suspend the ACPI.sys driver, but it will cause your whole laptop to be in a very unstable mode where you an get BSOD often cuz your laptop cannot detect the usage and temps of your CPU, so once the CPU hit a rather high value in usage or temps, your laptop will just BSOD to protect the CPU.


Is there really no way that I can isolate the CPU cores used up by ACPI.sys from my DAW while I still can charge my laptop without having any audio dropouts or massive CPU spikes in my DAW?
Or any other ways?

*no need to tell me to use a desktop, because I don't own one plus I am always on the go, so laptop is way more practical for me*

Anyways, I would be really happy if anyone out there knows a way to solve this nightmare 

UPDATE: i managed to isolate the CPU cores with Process Hacker 2 and Process Lasso. But my CPU still spikes as long as i plug in my charger to charge the laptop.
Is there something wrong with my laptop?


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## Solarsentinel (Jun 23, 2021)

Unfortunatly it a major problem difficult to solve. I m currently searching the same answer, and for now i didn t find it, but if i found something i'll post it here.


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## Solarsentinel (Jun 25, 2021)

I don't think you can eradicate the ACPI.sys totally. But you can decrease the latency with "classical audio windows optimization" in order to have a latency under 400ms with this particular driver.

In order to do that:
- Priorize set the piority to back services,
- Use high performance power plan or ultimate if you have access to it,
- Set the energy saving off usb to off
- Set max performance 100% for the cpu usage at min and max states,
- Deactivate all the stuff you don't need/use like bluetooth, wifi, audio drivers like realtek, webcam and so on...,
- If you can, push further on bios settings (but on laptop sometimes options are not available),
- Set your graphic card to max performance and no energy saving,
- Be sure to PLUG your power adaptator!! Working with the battery = high latency due to power saving.

These things usually get rid of dpc latencies, and at least slow down the latencies of your problematics drivers.
I don't go deeper here because there is some other posts on that subject available on the web. Good luck with this!


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## fakemaxwell (Jun 25, 2021)

Have you turned off SpeedStep (or AMD equivalent) and disabled C-states?


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## Matt Donovan (Jul 11, 2021)

I have the same DPC nightmare on a Lenovo T480 laptop configured with 64GB RAM. I have tried just about everything.


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