Difference between CPU usage and CPU utilization ?


could you pls clarifty the difference between "CPU usage" and "CPU utilization" metrics for IBM Power Systems ?




  • Hi,

    ok, you testing Xormon NG where it is used, but not documented yet.


    CPU usage: CPU allocation to a partition (it is how HMC/server sees it)

    CPU utilization: real CPU usage by processes, it is always lower (it is how the OS sees it), the OS unused asigned CPU utlize by CPU idle cycles

    In fact: CPU usage = CPU utilisation + CPU idle cycles

    There are 2 views for using of CPU, both are important

    Is that clear enough?

  • btw upgrade to the latest version if you want to test it, pls let us us know any feedback if possible, thanks :)


    uprade is easy, do it via the UI --> settings --> upgrade

    we are finishing it, bud there is still a lot of cosmetic issues to fix, finale release is schedulled in a few weeks.

  • Hello Pavel,

    are you sure it's not vice versa - i.e. CPU utilization are number of virtual CPUs allocated by partition (LPAR) and CPU usage is actual CPU usage of this CPUs - I'm comparing CPU utilization from current version of xormon and CPU usage from xormonNG and utilization is always higher.

    Also could you provide another link for the latest xormonNG update - the one above doesn't work for me.



  • sorry, there was missing a slash in the link: https://xormon.com/download-static/xormon-ng/xormon-ng-0.6.58.tar.gz

    IBM Power LPAR/CPU pool: CPU utilization in lpar2rrd/xormon should be equal to CPU usage in Xormon NG

  • Hello,

    in our case CPU utilization in lpar2rrd is significantly higher than CPU usage in XormonNG. (pls check the pictures below). Also there is no data displayed/collected for CPU utilization in XormonNG (see the screenshot).


  • CPU utilization: it might not be supported on old servers/HMCs, could that be the case? What is your env based on? what Power technology?

    CPU usage: the biggest server in Xormon (51.69), which one it is in Xormon NG graph (color)?

  • Hello,

    we are running Power8,9 and 10 generations. Biggest server in xormon is Power 10 enterprise server ( 1080).

    The reason I'm suggesting that CPU usage should be bellow CPU utilization is that "CPU usage" in xormonNG is comparable with "CPU usage" mectrics in Power HMC console



  • if you compare the biggest server as per utilization (the one with 50 cores running)

    what presents Xormon NG? X times less utilisation as I see the the biggest one running on 20 CPU cores in NG.

    Is that the same server?

    If so, there is 30 Core difference, can you confirm it?

  • Hello Pavel,

    here are screens from Xormon and XormonNG for the same biggest P10 server covering roughly same timeframe yesterday afternoon:

  • send us via email ( support at lpar2rrd dot com ) these daily graphs from this server from both tools, Xormon and Xormon NG

    • CPU pool graph
    • CPU Total
    • VM aggregated
    • what is CPU count in that server, 96 or 94?


  • sent an email with screenshots ....

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