IRQ 8 High Precision Event Timer is missing despite being active in BIOS and device manager?

Discussion in 'Operating Systems' started by xShino, Feb 17, 2022.

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  1. xShino

    xShino Member

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    Does anyone have an explanation why IRQ 8 is missing in my msinfo?

    [​IMG]

    I've tested using "bcdedit /set useplatformclock true" but it still didn't show up. The command just slowed down my OS by a lot. I've reverted it with "bcdedit /deletevalue useplatformclock" and now my "bcdedit" is untouched/default.

    OS: Windows 10
    Mainboard: ASRock Z390 Steel Legend
    CPU: Intel i7-9700K
     
  2. mbk1969

    mbk1969 Ancient Guru

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    Double click on High Precision Event Timer (in Device Manager) and check tab "Resources". I bet there is no IRQ allocated for HPET.
     
  3. xShino

    xShino Member

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    Hi @mbk1969

    I guess you are right?
    [​IMG]

    Why is that though or what does this affect? Is this mainly on newer boards, or is it an exception for mine?

    If possible I'd like to "force" HPET on (as a test), because I am not sure if it's active or not.
     
  4. mbk1969

    mbk1969 Ancient Guru

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    HPET does not need IRQ. It is a memory mapped access type of device.

    Upd:
    We know for sure that in Windows HPET is used as a timestamp counter:
    - read timestamp value "1";
    - then do some job;
    - then read timestamp value "2";
    - calculate the time span between two timestamps.

    No need for any interrupts.
     
    Last edited: Feb 17, 2022
    EdKiefer likes this.

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