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I know, yet another post of ACPI.sys sitting atop a CPU core. It's seems a different issue from the other posts, though, please, read on. The other proposed solutions didn't work!

  • It's a P65_67RSRP notebook, i7-6700HQ processor, Windows 10 64-bit version 1903.

  • Also, it seems to be a OS-agnostic issue, as it manifested itself also under the installed Manjaro KDE, with process kworker/0:2+kacpid using ~11% CPU!

  • I was able to fix the issue under Linux by disabling interrupt gpe6F (as suggested here: https://forum.manjaro.org/t/kworker-kacpid-cpu-100/131532)

  • The problem is that I don't know how to reproduce this fix in Windows!

  • It seemingly started after I installed a NVMe SSD from Intel alongside the other disks.** The new device model: INTEL SSDPEKNW010T8. So, the computer now has a 240GB PCI-e SSD (disk 0), a HDD (disk 1) and the NVMe (disk 2).

  • Nothing worked: No solution proposed in https://superuser.com/a/1164299/511946 worked. I've tried installing Intel drivers for the SSD to no avail. Disabling power management options didn't work for any device, network card included. No BIOS updates are due.

  • I investigated until I reached ACPI.sys as the culprit. I tracked the callstack with MPT and found this:

enter image description here

This image, the fix in Linux and the new SSD are certainly clues, but I can't figure them out.

Any tips debugging this?

Fernando D'Andrea
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  • One [post](https://answers.microsoft.com/en-us/windows/forum/all/acpisys-high-cpu-on-system-power-on-but-not/cfa4a944-cbeb-4e4e-9dec-654c5f004605) says this: "Workaround for me: restart system before logging into Win 10". Try rebooting from the Welcome screen. – harrymc Nov 28 '20 at 10:56
  • @harrymc No effect. – Fernando D'Andrea Dec 02 '20 at 20:52

1 Answers1

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Some possibilities:

  • In Power Options > Change plan settings, click "Restore default settings for this plan" and reboot
  • Disable the PCI Express Link State Power Management as described in this article and reboot
  • Boot in Safe mode and if it doesn't happen then some installed application is responsible for the problem
  • The post Why is the System process using 40-60% of CPU power all the time might also be of help.
harrymc
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  • None of the suggestions had any effect. :-( – Fernando D'Andrea Dec 05 '20 at 23:43
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    There may be many root causes for these problems, all different, so here are some more. (1) Check for a BIOS update. (2) Some people claim that it helps in the Ethernet card Properties to disable Wake-on-LAN (or Wake on magic packet). (3) Some others say the solution was to install the latest [Intel Rapid Storage Technology (RST)](https://downloadcenter.intel.com/product/55005/Intel-Rapid-Storage-Technology-Intel-RST-). – harrymc Dec 06 '20 at 09:39
  • I can trace the cause to the presence of the Intel 660p NVMe disk. So it somehow points towards installing the Intel RST thing, only it has no effect whatsoever. I actually reinstalled the system from scratch and got no effect. And the problem seems to be system agnostic, as it also happens exactly the same (a thread in the ACPI module sitting upon a core) in my Manjaro install. The difference? There's a simple line of command I can use in Linux to disable an interrupt with seemingly no ill effects in the system operation and all is fine. – Fernando D'Andrea Dec 07 '20 at 21:27