Windows 10 not showing all cores after change to VM cores

Discussion in 'Virtualized Computing' started by SpeedyVV, May 8, 2017.

  1. SpeedyVV

    SpeedyVV [H]ardness Supreme

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    I'm using UnRAID (KVM), and had a Windows 10 VM with 64 cores.

    Now I changed the VM to has 68 Cores, however Task Manager and Device Manager>Processors only still show cores/threads.

    Using HWInfo64 it does show that the system does indeed have 68 cores.

    Is there something I can do to "refresh" Windows to detect the added cores?

    I tried tried Scan for Hardware Changes in Device Manager, but it does not do the trick.
     
  2. Biznatch

    Biznatch [H]ard|Gawd

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    Did you reboot the VM? I don't think you can add vCPUs to a running windows instance without a reboot.
     
  3. SpeedyVV

    SpeedyVV [H]ardness Supreme

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    Yes, rebooted a few times. No luck.

    As a matter of fact the VM was powered off when I changed the core count.
     
  4. M0n0man

    M0n0man n00bie

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    Boot the VM with a linux distro and see if it shows the correct core count.

    Post back so we can further assist ;)
     
  5. k1pp3r

    k1pp3r [H]ardness Supreme

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    I bet its a GUI bug, if msinfo32 shows the correct processor, it should be fine.
     
  6. REDYOUCH

    REDYOUCH [H]ardness Supreme

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    Why the hell do you need that many cores in a VM?
     
  7. SpeedyVV

    SpeedyVV [H]ardness Supreme

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    Hodlcoin
     
  8. SpeedyVV

    SpeedyVV [H]ardness Supreme

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    Traveling in Australia, but will remote login tonight and report back.


    Edit: just logged on.
    Processor Intel(R) Xeon(R) CPU E5-2699 v3 @ 2.30GHz, 2295 Mhz, 32 Core(s), 64 Logical Processor(s)
     
    Last edited: May 13, 2017
  9. Quartz-1

    Quartz-1 2[H]4U

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    Are you running 32 bit Windows 10? That has a limit of 32 cores per CPU.
     
  10. SpeedyVV

    SpeedyVV [H]ardness Supreme

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    No, definitely x64
     
  11. QHalo

    QHalo 2[H]4U

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    You said you rebooted it, but did you power it off and back on? Typically in the VMware world, you need to do that for the VMX file to update to show properly. A reboot won't do it.
     
  12. muz_j

    muz_j [H]Lite

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    This got my curiosity. I've had a read and it definitely should work. Here's an article with examples re: the creation of Windows 8. It clearly shows the desktop OS in a VM displaying 64+ cores in Task Manager etc.

    https://blogs.msdn.microsoft.com/b8/2011/10/27/using-task-manager-with-64-logical-processors/

    I would follow the advice from QHalo re: the power off, but it sounds to me like you've got a weird OS issue specifically with task manager and device manager. You've confirmed that the correct core count is displayed re: System Info, which to state the obvious is run within the OS, therefore the OS is detecting the correct number.
    Weird, but interesting...
     
  13. SpeedyVV

    SpeedyVV [H]ardness Supreme

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    I'm starting to think that because the OS was installed with 64 threads, this is causing some bug to appear, or something got screwed up.

    When I return from my trip, I'm going to reinstall windows and see if this fixes it.