What is Turbo Boost?

Discussion in 'MacBook Air' started by Felasco, Mar 15, 2014.

  1. Felasco Guest

    Oct 19, 2012
    Hi all,

    What is Turbo Boost please?

    As example, MBA specs say....

    2.5GHz dual-core Intel Core i5
    Turbo Boost up to 3.1GHz
  2. maflynn Moderator


    Staff Member

    May 3, 2009
    It means that the clock rate for the CPU runs at 2.5GHz but if a demanding app is using a lot of CPU, it can run at 3.1GHz for short periods of time

    More detailed explanation can easily be found here: http://en.wikipedia.org/wiki/Intel_Turbo_Boost
  3. Dweez macrumors 65816


    Jun 13, 2011
    Down by the river
  4. Boyd01 macrumors 68040


    Feb 21, 2012
    New Jersey Pine Barrens
    What MacBook Air specs are you looking at? The 2013 model specs say


    1.3GHz dual-core Intel Core i5 (Turbo Boost up to 2.6GHz)

    or optionally

    1.7GHz dual-core Intel Core i7 (Turbo Boost up to 3.3GHz)
  5. Felasco thread starter Guest

    Oct 19, 2012
    Ah, I see now, many thanks for the education.
  6. Mrbobb macrumors 601

    Aug 27, 2012
    Maybe that's the reason why Activity Monitor can show OVER 100% load?
  7. jtara macrumors 65816

    Mar 23, 2009
    It boots the engines to Warp 10 until Scottie gets on the horn and says:

    "Captain! She canna take any more!"
  8. gnasher729 macrumors P6


    Nov 25, 2005
    No, that is because it shows 100% if _one_ core is running at 100%. A dual core Mac can go up to 200% if both cores are running at full speed, quad core up to 400%, and any Mac with hyperthreading can display twice as much.

    It doesn't actually say anything about the speed at which the processor runs, just that it runs 100% of the time.


    That's remarkably close to what happens. :D

    All the Intel CPUs are limited by heat production. The faster the chip runs, and the more work it does, the more heat. And if the heat gets too much and the fans can't take the heat away fast enough, the speed is reduced.

    The first number (say 1.7 GHz for some MBA model) means the processor can run all cores at 1.7 GHz 24 hours a day without getting too hot. But if you use only one core for a short time, it can go up to the "Turbo Boost" speed.
  9. yosemit macrumors regular

    Jul 19, 2013
    The Haswell processors in MBA 2013 seem to be able to run at 2.6GHz (for i5 and single threaded) and 3.3 GHz (for i7 and single threaded) for a long time, because those Haswell processors rarely overheat on non-GPU workloads.
  10. bjet767 macrumors 6502a

    Oct 2, 2010
    What is "Turbo Boost"

    "When Airwolf bolted across the sky in "turbo boost" mode, one would hear it "howl like a wolf" as it made a glass-shattering sound effect. When sitting idle, the aircraft made a mechanical trilling sound, and while hovering the rotor blades made a ghostly wind drone."

  11. kohlson macrumors 68000

    Apr 23, 2010
    Intel CPUs really can't go any faster (heat), and what many people really care about is battery life. So in a perfect world they would idle very as close to zero as possible, run background tasks or simple things at a low, rated speed, and ramp up into Turbo mode when extra CPU power is needed. Intel CPUs can do this, and run up as long as the total thermal envelope (the heat generated by all cores in the CPU) is no exceeded. Since many apps are single threaded (they use one thread of one core) this can be a big benefit - longer battery life and the power to encode video when needed. More here.

    Many Apple systems have either 400% or 800% capacity. The former is dual-core, each with 2 threads. MBA's are like this. The latter is quad-core, such as the 15-inch rMBP. MPs can have many more, but very few apps can take advantage of them simultaneously. But you can run more than one thing at once.
  12. Woodcrest64 macrumors 65816


    Aug 14, 2006
    Lol. Those were the days :)
  13. RightMACatU macrumors 65816


    Jul 12, 2012

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