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  • 1.  CPU overcommit ratio

    Posted Feb 09, 2024 11:32 AM

    Hello,

     

    What CPU overcommit ratio is the best for sizing?

     



  • 2.  RE: CPU overcommit ratio

    Posted Feb 09, 2024 12:00 PM

    Hello,

    It depends on the nature of your workloads.But for general puppose VMs, it is between 1/1 and 1/3.

    I suggest using Aria Operations (vROPS), it will gather information about environement and let you know the best sizing for your current workloads.



  • 3.  RE: CPU overcommit ratio

    Posted Feb 12, 2024 12:15 PM

    Hello, 

    Ratio 1/3 when hypertheading is enabled?

    As we know for intel cpu there are CVE about L1 Terminal Fault that we shoud disable the hyperthreading. 

    So with hyperthreading disable, can we still use ratio 1/3?



  • 4.  RE: CPU overcommit ratio

    Posted Feb 12, 2024 02:46 PM

    As   mentioned, 1:1 to 3:1 is no problem.

    If you disabled hyperthreading, you calculate the physical cores (pCPU) on the host.



  • 5.  RE: CPU overcommit ratio

    Posted Feb 12, 2024 02:49 PM

    so we can say the overcommit ratio is 1:1 if hyperthreading is disable?



  • 6.  RE: CPU overcommit ratio

    Posted Feb 12, 2024 03:07 PM

    if hyperthreading is disable you have for example:
    2 Processor Sockets X 12 Cores =  24 pCPU

    You can allocate 72 vCPU without performance degradation. 
    The actual achievable ratio depends on several factors



  • 7.  RE: CPU overcommit ratio

    Posted Feb 12, 2024 03:13 PM

    How if hyperthreading enabled? Will i have 144 vCPU?