ProcExp: Process cycle counts erroneously scaling with clock speed RRS feed

  • Question

  • It seems that cycle counts are scaling proportionally with per-process % load between different clock speeds. I'm pretty sure cycle counts should never scale like that, especially since performing 4.4B cycles (4.4Ghz) on a logical core that's running at 1.4Ghz is not possible. Here are my notes on it:

    My 3C/6T CPU at 4.4Ghz (hard locked all-core clock):
    There are ~26,832,500,000 cycles per second in 100% load

    1.4Ghz (locked using Windows powercfg profiles)
    There are ~27,982,665,133 cycles per second in 100% load. Roughly the same as before

    27B cycles / 6 logical cores = 4.5Ghz: Maybe their cycles reading is slightly inaccurate, but generally lines up with my max CPU speed

    Here's a bit of ooold patch notes for when % load changed to adhere to cycle counts:

    Process Explorer shows actual CPU usage now based on cycle counts. If you have speedstep or other CPU frequency throttling enabled that will cause work consuming some number of cycles to be calculated as a higher percentage of available cycles per second.

    Me talking now:

    I pin it down to a software bug in PE. % load is supposed to go up on lower speeds yes, but cycles shouldn't also be multiplied by that same factor


    • Edited by hoffry Saturday, July 11, 2020 4:20 PM
    Friday, July 10, 2020 8:07 PM