Macbook CPU Whine Driving Me Insane.

Discussion in 'MacBook' started by brianr19, Aug 5, 2010.

  1. Fast/Furious macrumors regular

    Fast/Furious

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    Oct 18, 2008
    Location:
    Vancouver, BC
    #2
    Prop it up and off the table to allow maximum airflow.. also see if you have a piece of plastic film covering the air outlet (many MacBooks had these from the factory and were not removed properly). If all else fails, open it up and clean the CPU/heatsink assembly of dust. Hope this helps :)

    EDIT: Also try downloading SMCFanControl to throttle up/down your fan speed. However, usually there is a reason for the fans spooling up so loud and fast so I don't recommend that you use SMC to lower the fan speed :)

    Help.
     
  2. andalusia macrumors 68030

    andalusia

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    Manchester, UK
    #3
    Undescriptive Thread Driving Me Insane.

    Help.
     
  3. brianr19 thread starter macrumors member

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    Nov 7, 2008
    #4
    I'm not sure if it is the CPU making this sound. It's coming from the upper left of the keyboard. It's a high pitched sound and it is constantly there. If I use a lot of CPU (like open PhotoBooth) it stops.

    Help.
     
  4. Fast/Furious macrumors regular

    Fast/Furious

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    #5
    That's called a fan. Help.
     
  5. brianr19 thread starter macrumors member

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    Nov 7, 2008
    #6
    Not even.
     
  6. brianr19 thread starter macrumors member

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    Nov 7, 2008
  7. brianr19 thread starter macrumors member

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    Nov 7, 2008
    #8
    Nobody has this problem? I read somewhere that every Macbook has this problem and no fix for it? I don't wanna have to go back to Windows... :mad:
     
  8. andalusia macrumors 68030

    andalusia

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    #9
    Of course there's a fix for it! I'm surprised nobody else said it, I assumed they would which is why I didn't.

    Earplugs.
     
  9. TreborM macrumors member

    Joined:
    Jun 26, 2010
    #10
    Lots of people have this problem but this is not fan or CPU.

    What you hear is the switch mode power supply - to be precise current "whinning" in the inductor ... there is nothing an average person
    can do about it. It will go away as soon as load increases.
     
  10. DoFoT9 macrumors P6

    DoFoT9

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    #11
    while there is a chance that it is the PSU, there actually are reported issues about the CPU making some sorts of noises.

    also, the GPU in some specific cases, my GFs MBP does it.

    the fix? there is none. put up with it.
     
  11. TreborM macrumors member

    Joined:
    Jun 26, 2010
    #12
    Ohh please... What are you trying to say? That a piece of a silicon is making
    noise ? No offence but this is rubbish ...

    Please provide at least solid explanation (in terms of physics phenomena) how theoretically CPU or GPU can make a sound?
     
  12. DoFoT9 macrumors P6

    DoFoT9

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    #13
    hey, im no engineer, but i can diagnose a problem when i see/hear/experience it.

    - no scrolling in Safari - computer doesnt make a noise..

    - scrolling in Safari - weird whine comes from the computer, very similar to this, this, this, this and this.

    a few of those links indicate capacitor whine, or faulty fans etc. but it doesnt sound like them at all.
     
  13. wordoflife macrumors 604

    wordoflife

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    Jul 6, 2009
    #14
    Put more descriptive information.

    Help.
     
  14. Hellhammer Moderator

    Hellhammer

    Staff Member

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    Finland
    #15
    The PSU is external silly ;)

    If you told us what MacBook you have, it would be easier to help. The current gen has CPU and GPU near the location you described but not sure about older models
     
  15. DoFoT9 macrumors P6

    DoFoT9

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    #16
    the inverter thingo then, what Trebor said ;)

    its a 2008 Penryn 8600M MBP machine.

    when i put my ears very close i can hear it coming from all parts of where the screen connects to the board (roughly).
     
  16. NJuul macrumors 6502

    Joined:
    Mar 15, 2006
    Location:
    Boston
    #17
    I thought this was only a problem on the original (2006) MBP's..
    The "CPU" whine (it was really the inverter) would be extremely high when the mac was throttling down from it's highest speed setting. It was even a documented issue with apple, and they would replace the logic board if it was too severe.
    Anyway, I haven't encountered it on any mac since, but if you have it, there is nothing to do about it except make sure your mac runs at a speed setting where it isn't noisy (ie., make sure to do some work on it!). If it is really high, you might get Apple to replace the logic board.
     
  17. TreborM macrumors member

    Joined:
    Jun 26, 2010
    #18
    Well ... not precisely :) - you are experiencing something but you are not
    exactly diagnosing it - you are assuming an explanation

    Simplifying things a bit it is impossible for a capacitor to make whining sound.

    For those interested more detailed explanation of this issue:

    Modern digital electronics (especially computers) use big, power hungry chips like CPU or GPU. Chips like that in order to keep the power dissipation at bay must be powered using lowest possible voltages (because P = U x I).

    This means that designer of the system needs several stabilised rails capable of delivering literally tens of amps at few volts. The name of the game here is miniaturisation and efficiency so virtually all of them use something called step-down DC converter (http://en.wikipedia.org/wiki/DC-to-DC_converter).

    To design step-down converter which is small and efficient will in 99% of the cases mean switch-mode conversion with an inductor which stores the input energy temporarily and then releases that energy to the output at a different voltage. This is usually done at frequencies ranging from hundreds of kHz to several MHz.
    Often there is more than one, with some really hungry chips (like GPU) having dedicated converter/stabiliser.

    Finally we are arriving at the issue at hand:
    Properly designed and built switching mode magnetic converter will be inaudible.

    Unfortunately in real life this is not always the case, and many of them will
    make whining sound from the inductor when the converter is not built (or designed) perfectly. Usually inaudible hum is due to vibration of windings in the inductor and/or magnetostriction.

    This is especially true when switched mode converter is not loaded because it then operates at the lowest frequency (which in extreme cases could be straight in the top of audible human range).

    The only possible fix for the issue is to replace the inductor ... not something
    which could be recommended to an average person.

    All of the above is greatly simplified, but the bottom line is (like DoFoT9 rightly pointed out) that we all have to leave with it.
     
  18. DoFoT9 macrumors P6

    DoFoT9

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    #19
    nice explanation, thanks - so basically, its coming from the inductor? is it directly related to power draw, because i highly doubt scrolling in safari uses any more then minimal power draw during that time?
     
  19. TreborM macrumors member

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    Jun 26, 2010
    #20
    Sadly my 2010 MBP does it as well but not always - I could go on about it for ages but long story short this kind of a problem depends an ambient temperature AND humidity as well ...
     
  20. TreborM macrumors member

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    Jun 26, 2010
    #21
    Well there are two answers to this question:
    - first I am guessing that in this particular case you actually hear the GPU power supply, and scrolling the screen would put small load on it
    - and again guessing but most modern controllers will reduce their frequency dramatically when idling. This means that putting even the smallest loaded on it will kind of "wake it up" and it will instantly go quiet
     
  21. designgeek macrumors 65816

    designgeek

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    #22
    I can totally hear the sound when scrolling. I thought I was crazy. I might still be, wanna join me OP? ;)
     
  22. DoFoT9 macrumors P6

    DoFoT9

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    #23
    the said noise can be heard whenever scrolling - even for a lengthened period of time. but i guess engaging it increases load/power demand JUST enough for it to be audible. i am unable to hear it when gaming/high load on GPU etc.

    thanks for your explanations - i see you are knowledgeable in this area :)
     
  23. TreborM macrumors member

    Joined:
    Jun 26, 2010
    #24
    You are probably talking about something slightly different (although still originating in the one of the down-converters). It is entirely possible that your sound card is picking up the noise from power supplies (most likely via ground).

    If it is high-pitch, kind of hissing sound coming from the speakers (which you can easily confirm by plugging in the earphones which disconnects speakers) it's noise pick up, if it's still there then probably sound is coming directly from one of the converters (inductors)...

    Still something that cannot be (easily) fixed.
     
  24. DoFoT9 macrumors P6

    DoFoT9

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    Singapore
    #25
    i will test it on both ground and non ground connections (australia has both) and get back to you. i will also check the speaker issues :) its SO annoying when its quiet :rolleyes:
     

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