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WMI Raw Performance RRS feed

  • Question

  • Hello

    I'm a bit confused how to use WMI raw performance, I have fund the formulas of the specific counters on TechNet, but the formulas are really cryptic about what values from to actually use, I'm trying to get a bunch of different performance data from WMI, but fx. AvgDiskQueueLength, when using the formula from TechNet and also specified on various sites I have found I get really wacky numbers.

    When using my own I get very close to what perfmon is showing...

    Formula use from TechNet:

    (TB(X1-X0)) / (Y1-Y0), where TB represents the performance frequency time base, the denominator (Y) represents the performance time measurement, and the numerator (X) represents counter data.

    (Frequency_Sys100NS * (AvgDiskQueueLengthNew - AvgDiskQueueLengthOld)) / (Timestamp_Sys100NSNew - Timestamp_Sys100NSOld)

    Home cocked formula which matches perfmon:

    (AvgDiskQueueLengthNew - AvgDiskQueueLengthOld) / (Timestamp_Sys100NSNew - Timestamp_Sys100NSOld)

    What is correct here? I'm sure TechNet formulas aren't bugged...

    Thanks,

    Jesper

    Friday, July 1, 2011 11:09 AM