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Optimal CPU Setup for RDS-Servers on AMD Epyc

  • 1.  Optimal CPU Setup for RDS-Servers on AMD Epyc

    Posted Dec 08, 2022 06:55 AM

    Hello,

    first off: I`m new here, hello everyone

    Since we got our new DELL PowerEdge R7525 with 2 AMD EPYC 74F3 24-Core Processor i am trying to wrap my head around the best CPU-Setup for your needs in this environment.

    My question is simple and i think since the paramenters are well known and do not change, someone can hopefully answer my question

    But first, our setup:

    Server: DELL PowerEdge R7525 with 2 Sockets
    CPU: 2x AMD EPYC 74F3 24-Core Processor | 96 Logical Cores
    RAM: 512GB
    GPU: 2x nVidia A16
    ESXi: 7.0.3 Build 20328353

    Since we do not use nVidias GRID technology on the hypervirsor but pass through the GPUs as PCI-devices (8 in sum) we will have no more than 8 VMs on this host. Therefore our initial VM Setup looked like this:

    10 vCPUs (10 Cores, 1 Socket) (in the attached Screenshots i reduced to 8 vCPU per VM)
    62 GB of RAM fully allocated
    PCI-Device of a GPU Attached
    EFI Boot
    Advanced Params:

    pciPassthru.use64bitMMIO

    TRUE

    pciPassthru.64bitMMIOSizeGB

    128



    The VMs are booting a Windows Server 2016 of a vDisk from Citrix Provisioning (Upgrade to Server 2019 is comming soon)

    In the BIOS of the DELL the relevat settings are these (default):

    NUMA Nodes per Socket: 1
    Number of CCDs per Processor: All
    Number of Cores per CCD: All

    As we got the VMs running on the surface everythings looks quite fine, but looking in esxtop I catched a feeling that something might be a bit off and could be better.
    Specifically:

    1. Since "only" 80 vCPU are assigned i would not expect %RDY times of sometimes around 2.0 - 3.0 (see attachment)
    2. NUMA: We see quite much remote NUMA access, i would excpect 100% home node use (see attachment)

    So what is the Ideal BIOS and VM Setup to get the best performance, considering that vMotion, DRS and so on is all turned of because of the attached PCI-Devices?

    I already read through this article where it states that since 7.0.2 everything is handled by vmware using EPYCs

    https://www.vmware.com/content/dam/digitalmarketing/vmware/en/pdf/techpaper/performance/vsphere70u2-cpu-sched-amd-epyc.pdf

    I hope i got all information needed in here and somebody can take a quick look at this setup.

    Thanks in advance, Timo