Throttling in Mac OS X (cMBP 2012)

Discussion in 'MacBook Pro' started by onerovico, Aug 1, 2013.

  1. onerovico macrumors newbie

    Jun 25, 2012

    my macbook pro has throttling issues in Windows (bootcamp) and in OS X. In windows there is no throttling problem (CPU/GPU) when it is running only ATITool's graphics test. But when i start Prime with 6 threads cpu and gpu start to throttle (Power adapter insufficient?).

    A similar problem appears also in OS X.

    1) Handbrake encoding video ==> Intel Power Gadget shows 3.4 GHz
    2) Handbrake encoding video and additionally I start "Geeks3D GpuTest" ==> Intel Power Gadgets shows something between 2-2.6 Ghz, GPU frequencies are unknown because there is no way to monitor them in OS X

    Maybe somebody with the same machine (2.6Ghz 2012 cMBP 16gb Ram) can try to reproduce the problem. In my opinion the problem is the following: 45 Watt CPU + 45 Watt GPU = 90 Watt < 85 Watt Power adapter

    PS: SMC reset doesn't help

    Attached Files:

  2. duervo macrumors 68020


    Feb 5, 2011
    If the power adapter was insufficient to meet load demands, I believe the battery may provide the power to make up the difference, and you would possibly see slight battery drain happening, depending on how long it's in that state.

    Prime is designed to stress the crap out of a system (it's a benchmark program.) If your system is throttling then that means it's doing what it's supposed to ... stress the crap out of your system, and your system's temps are high enough for the CPU/GPU to warrant throttling. If you don't want any throttling to happen, then increase cooling, which can done with one or more things from thermal paste reapplication, to running the benchmarks inside a walk-in freezer.
  3. onerovico thread starter macrumors newbie

    Jun 25, 2012
    Battery drainage is max. 3-4 Watts in OS X (while maximum Load). I also have the problem in games in Bootcamp for e.g. in Crysis 3 or COD Modern Warfare I see frame drops.

    (The Benchmarks were planed as an objective testing environment ;) )
  4. duervo macrumors 68020


    Feb 5, 2011
    Alright, I will put it a different way then ...

    Throttling is not due to the power adapter. It's due to temperature, which goes up as you stress the system, which you are doing by running Prime.
  5. onerovico thread starter macrumors newbie

    Jun 25, 2012
  6. leman macrumors G3

    Oct 14, 2008
    Maybe I am not getting something but why would you EVER run a stress test tool (which is designed to bring your hardware to its limits and beyond) while doing useful work?
  7. Doward macrumors 6502a

    Feb 21, 2013
    You can't surpass 100% of a system's capabilities, no matter how much you throw at it.

    I for one expect a system to manage 100% load for extended periods of time without complaint.
  8. sofianito macrumors 65816


    Jan 14, 2011
    What a disgusting picture... Is it a cow's intestines?

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