Turbo boost working in new Mac Pros?

Discussion in 'Mac Pro' started by VirtualRain, Mar 12, 2009.

  1. VirtualRain macrumors 603


    Aug 1, 2008
    Vancouver, BC
    Is there any way to measure if Turbo boost is functioning in OSX (i.e. a clock speed utility, CPU state utility, or even a core temperature utility)?

    If so, has anyone determined if Turbo boost is working on their MP and/or what temps the CPU's are running at under idle/load conditions?

    I'm concerned that the somwhat passive CPU cooling may not be sufficient to proivde the necessary TDP head-room necessary for Turbo Boost to kick in (maybe in low ambiant temps it might - without knowing the CPU core temps it's hard to say).
  2. ScottishCaptain macrumors 6502a

    Oct 4, 2008
    > I'm concerned that the somwhat passive CPU cooling...

    The "heatsinks" you see on the 2009 Mac Pro's are not heatsinks so to say. The large block of aluminum is nothing more then a shroud. Inside that shroud is a heatpipe system leading to several heatsinks, and an active fan that connects to the CPU board via a ZIF socket under the shroud, and some thermal sensors attached to the heatsink(s).

    That being said, each processor has it's own dedicated fan- above and beyond the two 120MM fans on either end of the CPU cage. The cooling solution isn't passive, it's definitely active. Though you can't see the individual CPU fans in most consumer-taken pictures, they're there.

  3. VirtualRain thread starter macrumors 603


    Aug 1, 2008
    Vancouver, BC
    Ahhh... thanks... that's reassuring.

    Is there anyway on a Mac to confirm if the CPU is changing state? (I suppose worst case there are plenty of tools under Windows to determine this)
  4. shokunin macrumors regular

    Jun 7, 2005
    I'd like to find an app that measures this too. I tried CPU-X, but it only shows the boot clock frequency. As the processor moves between states and turbo boost is kicked in, CPU-X does not refresh.

    According to Apple, the Xeon in the 2.93 has an additional 3x multiplier (3x133 BLCK=400mhz), which is higher than my i7 920, which has an additional 2x multiplier (2x133 BLCK = 266). Of course my BLCK is overclocked so the multiplier is (2x180 = 360mhz).

    Of course, this high of an boost is only available when ONE core is active. When two or more cores are active then a different multiplier is used. In my i7 920 when two or more cores are the max multiplier is and additional 1x multiplier.

    I couldn't find any documentation on the Xeon's and their max multiplier with, one, two, three, or four cores active. Theoretically, they have different max multipliers for when each core is active..

    In my BIOS on my i7 920. (These multipliers cannot be changed in Bios, it's set by the processor)

    One Core turbo boost = 22x multiplier
    Two Cores Active = 21x
    Three Cores Active = 21x
    Four Cores Active = 21x
    No Turbo Boost = 20x (20x133 BLCK = 2.66ghz stock speed)
  5. nanofrog macrumors G4

    May 6, 2008

    I certainly didn't see the fans, and was under the impression the 120mm's where all there were. Though I'm still a little concerned about the orientation of the airflow. :confused:

    Temps under load would be nice. :)
  6. 65StangBoy macrumors member

    Dec 29, 2007
    I can confirm that there are heatpipes and a fan within the heatsink.

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