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MygodStudio Honor Student
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ACPI.sys/hal.dll uses up a core usually after suspend

HP Spectre x360 Laptop - 13t touch 7FQ48AV_1
Microsoft Windows 10 (64-bit)

My system process eats up a core CPU sometimes, usually after a combination of suspending and connecting external monitor through Thunderbolt 3 (not sure in what order). I still cannot reproduce this reliably but it happens every week. A reboot always solves the problem but it is still very annoying.


perf dump shows that acpi.sys/hal.dll is doing some getting bus data. Help?



Laptop details:

  • Dark ash silver
  • 13.3" diagonal FHD IPS micro-edge WLED-backlit multitouch-enabled edge-to-edge glass with Integrated Privacy Screen(1920 x 1080)
  • No DVD or CD Drive
  • 1 TB PCIe® NVMe™ M.2 SSD
  • Full-size island-style backlit keyboard (Dark Ash Silver) (Privacy Screen)
  • Security Software Trial
  • Intel® 802.11b/g/n/ac (2x2) Wi-Fi® and Bluetooth® 5 Combo(MU-MIMO supported)
  • Office Software Trial
  • Windows 10 Home 64 Plus
  • Aluminum with FHD Webcam + IR Touchscreen (Dark Ash Silver)
  • 4-cell, 61 Wh Lithium-ion Battery
  • Intel® Core™ i7-8565U (1.8 GHz, up to 4 GHz, 8 MB cache, 4 cores)+Intel® UHD Graphics 620+ 16GB onboard
  • No Wireless WAN
  • HP Pen (dark ash silver)
  • HP Spectre x360 - 13t Touch Laptop
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ACPI.sys/hal.dll uses up a core usually after suspend

Thank you for posting on the HP Support Community.


You may be facing the above issue due to some of the system performance of the PC with the operating system. Sometimes running simple troubleshooters will resolve the performance issue. ( Microsoft suggestion ) 


Method 1: I suggest you to run System Maintenance troubleshooter and check if the issue persist.


Running System Maintenance troubleshooter will find and clean up unused files and shortcuts present on the system and perform maintenance tasks which will enhance the performance of the PC.


  1. Press Windows logo key on the keyboard, type Troubleshooting and select the top most search result.

  2. Select View all from the left side panel of the window.

  3. Select System Maintenance from the listed options, click on Advanced option and check Apply repairs automatically option.

  4. Follow the on screen instructions.

Method 2: Update the latest system software and driver using Windows Update and HP Support Assistant:

To check for updates now, select the Start button, and then go to Settings  > Update & security  > Windows Update, and select Check for updates.

Install updates from HP Support Assistant: Go to Download HP Support Assistant to install the tool.

  1. To open HP Support Assistant, double-click the HP Support Assistant icon
  2. Click My devices in the top menu, and then click Updates in the My PC or My notebook pane.
  3. Click Check for updates and messages to scan for new updates.
  4. Review the list of updates. Updates with a yellow information icon are recommended. Updates with a blue information icon are optional.
  5. Click the update name for a description, version number, and file size.
  6. Select the box next to any updates you want to install, and then click Download and install.

Hope this helps! Keep me posted for further assistance.
Please click “
Accept as Solution” if you feel my post solved your issue, it will help others find the solution.

I am an HP Employee

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MygodStudio Honor Student
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ACPI.sys/hal.dll uses up a core usually after suspend

This did not resolve the issue.

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ACPI.sys/hal.dll uses up a core usually after suspend

@MygodStudio I recommend performing a hardware test to identify the cause of the malfunction, and ensure this isn't a hardware issue:

Install the latest version of the HP Hardware diagnostics (UEFI) on your device using this link: Click here for details

  • Hold the power button for at least five seconds to turn off the computer.
  • Turn on the computer and immediately press Esc repeatedly, about once every second. When the menu appears, press the F2 key.
  • On the HP PC Hardware Diagnostics (UEFI) main menu, click System Tests.
  • Click Extensive Test.
  • Click Run once, or Loop until error.
  • While the test is running, the time remaining and test result for each component display on the screen.

If a component fails a test, write down the failure ID (24-digit code) for when you respond back to us.

If you wish to thank me for my efforts, you could click on "Accept as solution" on my post as the solution should help others too.

I am an HP Employee

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