One of my cores keeps shutting down?

Discussion in 'MacBook Air' started by Mr.Green, Feb 7, 2008.

  1. macrumors member

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    EWR
    #1
    I noticed this morning that one of my cores shuts down during heavy load. This has never happened on my Macbook Pro. See attached jpg.

    Anyone else have this problem?

    Is it due to heat?
     

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  2. NAG
    macrumors 68030

    NAG

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  3. macrumors 604

    thejadedmonkey

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    #3
    Your MBA is (on average) around 60º+ hotter then my MBP is right now. Your fans are also on max... so yes, I'd say that's very possible.
     

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  4. NAG
    macrumors 68030

    NAG

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    #4
    Remember guys, temperature can be represented either in ºC or ºF (or kelvin, I suppose).

    Your CPU is running about 20ºF higher than his is, by the way.
     
  5. macrumors member

    Joined:
    Feb 1, 2008
    #5
    What utility are you using to get the temperature and fan speed?

    I.e., I figured out how to get the Activity Monitor... :cool:
     
  6. NAG
    macrumors 68030

    NAG

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  7. macrumors member

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    #7
    Sweet, that was painless to install!
     
  8. macrumors Penryn

    Eidorian

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  9. macrumors 68020

    noodle654

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    #9
    Could be the first major MBA problem?

    I must say that 158* is pretty high...call up Apple.
     
  10. macrumors G5

    Consultant

    Joined:
    Jun 27, 2007
    #10
    He is using it to encode movies. See ffmpeg/VisualHub

    In addition, he has apps open for torrents, music, video(s), and browsing web.
    Well, at least he's not trying to play Crysis at the same time. =p

    Translation = full CPU usage = heat
    Might want to get a laptop cooler...
    I am thinking about building one with 120mm quiet fans instead of a store bought that are fairly loud.
     
  11. macrumors Penryn

    Eidorian

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    #11
    I'm sure you've never seen a Macbook or Mac mini hit 190° F then.
     
  12. TEG
    macrumors 604

    TEG

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    #12
    Most systems are not suppossed to get above 70c. The reason for the core shutdown is three fold, 1) to reduce heat, 2) to save power when not needed, 3) to save battery life when unplugged.

    You should be able to deactivate this "feature" by selecting "maximum" as your processor speed in the energy saver preference pane.

    TEG
     
  13. macrumors 6502a

    Joined:
    Jun 7, 2003
    #13
    Well you're running VisualHub when this happens right so it's not all surprising that that's happening really.

     
  14. macrumors regular

    mactastic1971

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    #14
    I know the real memory looked small but there seemed to be ahelluva lot of virtual memory. Could that be swapping in and out causing IO wait or something ???
     
  15. NAG
    macrumors 68030

    NAG

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    #15
    Nah, just because there is a lot of virtual memory allocated doesn't mean there is a lot of swapping going on. We'd have to see his memory tab to know more.
     
  16. macrumors regular

    mactastic1971

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    #16
    Its just I've seen issues in linux where it automatically caches virtual memory for the last used applications and it will keep doing this until all the real memory is used. Then if the kernel needs to do something, one of my other cpus can drop out...

    Again... linux... not osx...
     
  17. NAG
    macrumors 68030

    NAG

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    #17
    Yeah, I was just commenting that we need more information to say anything conclusive about that.
     
  18. macrumors member

    Joined:
    Jan 15, 2008
    #18
    Hmm... just discovered that watching streaming 720p episodes of Lost from the ABC site overloads the processor and causes intermittent core shutdown. Annoying because it then gets all choppy and unwatchable.

    That's a shame.
     
  19. thread starter macrumors member

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    #19
    I was primarily encoding video using VisualHub for my iPhone, and downloading something with Transmission. The computer was sitting on a marble table in my hotel room.

    On my Macbook Pro, I am able to run the processors at 100% all day long encoding video. The fans would spin up at max and be very noisy, but I could do it if I wanted and the cores have never shut down like this. My first Macbook Pro, the core 1 duo, would sometimes even reach 85-90 degrees C / 185-194 F. My rev 2, Macbook Pro doesn't ever get that hot.

    The processor on my Air almost never even reached 100%. I would have expected in the Air, Apple should have tested it and designed it so it could run at 100% without overheating and triggering a CPU shutdown.

    I love my Air, but I think this is a mistake. Apple does like to push the thermal envelope all the time and I think they went a bit too far. Hopefully there would be a software fix for this.
     
  20. macrumors 6502a

    Joined:
    Jun 7, 2003
    #20
    Anybody installed Menu Meters on the air so you can see this activity in the menu bar all the time? That would be rather revealing.

     
  21. macrumors Penryn

    Eidorian

    Joined:
    Mar 23, 2005
    Location:
    Indianapolis
    #21
    Seems like utilizing the processing power of the dual core processor is going to make it a single core anyways.

    Hopefully it won't melt your laptop. Then again Apple changed the thermal tolerances and fan speeds for the G5 in Leopard.

    *cough*Thicker laptop*cough*
     

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