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  • 1.  Maximum vCPUs per logical cores

    Posted Mar 25, 2013 03:51 PM

    What is the maximum number of vCPUs that are recommended per logical core?  If I am NOT contstrained in terms of available GHz, when are there "too many"  vCPUs  logical core?



  • 2.  RE: Maximum vCPUs per logical cores

    Posted Mar 25, 2013 03:54 PM

    IMO this mainly depends on the physical resources and the capabilities of the guest OS itself. Regarding host usage there's no difference between vCPUs and cores-per-socket other than the presentation to the guest.


    André



  • 3.  RE: Maximum vCPUs per logical cores

    Posted Mar 25, 2013 05:04 PM

    In vSphere 5.1

    Maximum vCPU's per host is 2048

    Maximum vCPU's per core is 25

    In vSphere 4.1

    Maximum vCPU's per host is 512

    Maximum vCPU's per core is 25



  • 4.  RE: Maximum vCPUs per logical cores

    Posted Aug 20, 2013 09:08 PM

    I would like to ask for my own clarification regarding the vCPU to core aspect. Is core in this case referring to logical cores (logical processor) or physical core? I ask due to the below section taken from the "Virtual CPU Limitations" section of the vSphere Documentation Center. The reference to the hyperthreaded proc being called a "logical core" is what I am referring too. What I am trying to determine is the very thing that the TheVMinator has asked.

    "A virtual machine cannot have more virtual CPUs than the
    number of logical cores on the host. The number of logical cores is equal to the
    number of physical cores if hyperthreading is disabled or two times that number
    if hyperthreading is enabled."

    Thank you much for any information.



  • 5.  RE: Maximum vCPUs per logical cores

    Posted Aug 20, 2013 09:24 PM

    It would be 25 vCPUs that is referenced in virtualbuddy's answer since a Logical CPU equates to a core whether it is a phyical core or a hyperthread -



  • 6.  RE: Maximum vCPUs per logical cores

    Posted Aug 20, 2013 09:33 PM

    Thank you much.