Power

 View Only

  • 1.  Allocating more than 64 CPUs to a partition

    Posted Fri February 07, 2025 10:00 AM

    We have a 9080-HEX system with 120 CPUs (8x15 CPU modules). We would like to create one large partition with all the CPUs and memory (8TB) assigned to it. But the HMC limits the partition to just 64 CPUs. Is there a setting I'm missing or is this how the system is designed to run?

    The entitlement/COD appears fine as I can create 2 partitions, each with 60 CPUs so all the CPUs are available.

    Colleen



    ------------------------------
    Colleen Hayase
    ------------------------------


  • 2.  RE: Allocating more than 64 CPUs to a partition

    Posted Wed February 12, 2025 04:54 PM

    I asked to Gemini:

    The maximum number of CPUs that a Power10 LPAR can have depends on a few factors:

     * Power10 System Model: Different Power10 systems have different maximum core counts. For example, the Power E1080 supports up to 60 cores per processor, while other models have lower limits.

     * LPAR Type: Whether the LPAR is a shared processor LPAR or a dedicated processor LPAR affects the maximum number of cores it can have. Shared processor LPARs have limits on the number of virtual processors, while dedicated processor LPARs are limited by the physical cores available.

     * Firmware Level: The firmware level of the Power10 system can also impact the maximum number of virtual processors allowed in a shared processor LPAR.

    General Information:

     * Power10 systems can have up to 16 CPU sockets.

     * Each Power10 processor chip has 15 SMT8 cores or 30 SMT4 cores.

     * The maximum CPU clock rate for Power10 processors is +3.5 GHz to +4 GHz.

    Finding Specific Information:

    To determine the maximum CPU for a specific Power10 LPAR, you need to consider the specific Power10 system model, the LPAR type, and the firmware level. You can find this information in the IBM documentation for your specific Power10 system.

    Additional Resources:

     * Power10 - Wikipedia: https://en.wikipedia.org/wiki/Power10

     * 10 Things to Know about IBM Power10 Scale Out & Mid-Range Systems - Mainline: https://mainline.com/blog-10-things-to-know-about-ibm-power10-scale-out-mid-range-systems/

     * Shared processors - IBM: https://www.ibm.com/docs/en/power10?topic=processors-shared

     * 9080-HEX EDP4 60-Core IBM Power10 Processor E1080 - Midland Information Systems: https://www.midlandinfosys.com/9080-hex-edp4-60-core-ibm-power10-processor-e1080

     * Power10 Planning and Requirements - TechChannel: https://techchannel.com/power10/power10-planning-and-requirements/



    ------------------------------
    Cesar Daniel Delgado Ponce
    ------------------------------

    Original Message


  • 3.  RE: Allocating more than 64 CPUs to a partition

    Posted Fri February 14, 2025 07:30 AM

    Can you state the details of your HMC version, server firmware version, which OS, which OS version and what Power CPU compatibility mode you are using?
    I am thinking perhaps the LPAR in in POWER8 mode (or something) and that is causing the limit.



    ------------------------------
    Nigel Griffiths - IBM retired
    London, UK
    @mr_nmon
    ------------------------------

    Original Message


  • 4.  RE: Allocating more than 64 CPUs to a partition

    Posted Fri February 14, 2025 07:43 AM

     I didn't see my inquiry for a day or two after I submitted it and have been so busy at work I haven't had the time to update it.

    This was a red-herring. Our large partition may not display all CPUs when it is at the SMS menu but once an OS is installed it sees all processors. It was just very confusing that SMS only sees 64 CPUs while the remainder shows up as "available."

    I'm very sorry if anyone spent time thinking about it. It took a few days after my post before someone on my team had time to install the OS on this partition.



    ------------------------------
    Colleen
    ------------------------------

    Original Message


  • 5.  RE: Allocating more than 64 CPUs to a partition

    Posted Fri February 14, 2025 08:38 AM

    No problem at all and this is a very interesting observation.



    ------------------------------
    Nigel Griffiths - IBM retired
    London, UK
    @mr_nmon
    ------------------------------

    Original Message


  • 6.  RE: Allocating more than 64 CPUs to a partition

    Posted Mon February 17, 2025 08:11 AM

    Glad that it all came together.
    Have a good time with thousands of rPerfs under the hood .



    ------------------------------
    Alan Fulton
    Follow me on Twitter - @The_Iron_Monger
    ------------------------------

    Original Message


Related Content