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OS X & and its EIST (un)support

Discussion in 'Mac OS X 10.7 Lion' started by meme1255, Jul 16, 2012.

  1. meme1255, Jul 16, 2012
    Last edited: Jul 16, 2012

    macrumors 6502

    I am making small research about EIST support in OS X - please, insert in Terminal this commands :
    sysctl hw.cpufrequency_min
    sysctl hw.cpufrequency_max
    sysctl hw.cpufrequency

    and post here what it prints.

    Thank you ;)

    My example:

    MBP:~ Martin$ sysctl hw.cpufrequency_min
    hw.cpufrequency_min: 2530000000
    MBP:~ Martin$ sysctl hw.cpufrequency_max
    hw.cpufrequency_max: 2530000000
    MBP:~ Martin$ sysctl hw.cpufrequency
    hw.cpufrequency: 2530000000
  2. macrumors 6502

    Could someone post her/his result here? :(
  3. Mal
    macrumors 603


    2300000000 for all three commands.

  4. macrumors 6502

    Well... Thank you ;)

    It really looks like Apple DOES NOT use CPU-Powersaving technologies.. WHY?!
    (Or the terminal is lying, but i don't think so)
  5. appletechpro, Jul 16, 2012
    Last edited: Jul 16, 2012

    macrumors regular

    I think you are mistaken, and I wouldn't read too much into those sysctl values -- the newer CPUs obviously have TurboBoost and are advertised by Apple as such:


    EDIT: I included that information to illustrate that OS X obviously supports frequency scaling, but upon further review it appears there is conflicting information on the 'net. Wikipedia states SpeedStep support has been built-in the Darwin kernel since OS X Tiger, but there don't appear to be any recent confirmations of SpeedStep actually being utilized by Apple and the sysctl values in OS X are not modifiable.

    My guess is that OS X had SpeedStep support built-in to the kernel for good measure, and it probably hasn't been utilized by Apple in most of their products or possibly even at all.
  6. macrumors 6502

    It looks like Tiger supported it, but then it was removed ( and XNU don't contain speed step support, so Wiki is not accurate.)
  7. meme1255, Jul 17, 2012
    Last edited: Jul 17, 2012

    macrumors 6502

    Appears like SL don't support EIST, too :(

    hw.cpufrequency_min: 2530000000

    Attached Files:

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