Windows 7 - Why does my CPU usage spike when my monitor goes to sleep?

Discussion in 'Operating Systems' started by theevilsharpie, Jan 10, 2013.

  1. theevilsharpie

    theevilsharpie Platinum Member

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    This behavior has been bugging me for a while.

    When I leave my computer alone for a few minutes and my monitor goes to sleep, some process starts consuming a bunch of CPU time. I can tell that my CPU is being used, because my CPU's temps rise and the CPU fan speed increases to compensate.

    I've tried using perfmon to track down the process using the CPU usage, but Windows' performance logging is worthless and I wasn't able to find anything conclusive.

    Does anybody have any ideas what's causing this behavior? This has happened across multiple machines, so I'm pretty sure this is something internal to Windows, and not something caused by 3rd party software. When my monitor goes to sleep, my hard drives start going nuts as well, so I'm guessing this might be either the search indexer doing its thing, a quick defragmenting process, or the Windows memory manager paging out to disk.
     
  2. Nothinman

    Nothinman Elite Member

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    Did you try running perfmon from another PC? It's most likely some scheduled task, I believe you can set a trigger for something to run when a PC sleeps/resumes.
     
  3. theevilsharpie

    theevilsharpie Platinum Member

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    Perfmon shows that something is spiking. Unfortunately, that "something" is running within svchost, as are about half the processes on my PC. Since perfmon doesn't track the PID of a process (only the name), I have no way of knowing which svchost instance is misbehaving without interacting with the computer. Unfortunately, the instant I do, the behavior stops.

    I also tried using Process Explorer, but for some reason, it doesn't graph the CPU usage of individual processes other than the System Idle Process.
     
  4. paul878

    paul878 Senior member

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    Indexing?
    turn it off and see.
     
  5. Randum

    Randum Platinum Member

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    Did you ever get this fixed? Looks like I have a similar thing going on...
     
  6. Bubbaleone

    Bubbaleone Golden Member

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    I prefer Sysinternals Process Explorer v15.3 since it specifically identifies each process PID and shows you information about which handles and DLLs processes have opened or loaded.
     
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