I'm running a HP ProLiant DL380G6 with 2x Intel® Xeon® E5520 Quad Core Processor 2.26 GHz and 12GB of ram. I got Hyper-V installed and 3 VMs for now. If I open up task manager I can see 16 cores (I'm guessing that's 8 cores + 8 because of hyper-threading) but in Hyper-V I can only see 4 logical processors and as I read you are able to use 16 logical processors?

Best Regards, Acanthus

2 Answers 2


Hyper-V (on Windows Server 2008 R2) will run on a host system with up to 64 processor cores, but the supported number of cores available to guests varies depending on the guest OS (most Windows OS's are limited to 1,2, or 4 cores, and Linux guests to 1 core). See: Virtualization with Hyper-V: Supported Guest Operating Systems

  • Yeah...Maximum amount is 4 cores for virtualized R2 so all is good, thanks for the info.
    – Acanthus
    Dec 22, 2009 at 0:31

About 4 CPU core limit:

In VM's config file section:

[processors] [count type=”integer”]8[/count]

Now you have 8 core CPU.

This is my screenshot

  • 1
    It Doesn't Work That Way™
    – Chris S
    Aug 19, 2011 at 12:09
  • And this is my screenshot...
    – Nime Cloud
    Aug 19, 2011 at 14:53
  • From what I understand there are stability/compatibility issues with that hack. Hyper-V 3.0 (in Windows 8) will address these and give people the option to use up to 16 vCPUs.
    – Chris S
    Aug 19, 2011 at 20:30
  • I recently developed an application in C# which one consumes high CPU usage and needs more cores because of multi-threads. I'll give a try next weekdays.
    – Nime Cloud
    Aug 19, 2011 at 20:41

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