1 2 Previous Next 19 Replies Latest reply: Mar 23, 2013 12:29 PM by LormaD
andreigherghe Level 1 Level 1 (0 points)


I own a MacBook Air Mid-2009 (2,1) and it overheats really badly. In Lion it is even WORSE

I'm just browsing the web, no Flash, etc, and it gets VERY hot. This, in ~10 mins after i wake it up. Of course, kernel_task eats up the entire CPU then (140%) and it becomes unusable. The mouse barely moves.

The Air is a pretty powerfull machine (1.86 C2D, 2 Gigs of ram) but the cooling isn't enough. OR OS X takes actions too fast (at ~70 degrees celsius). I ran a simple test. I always hated Windows, but now it impressed me. On OS X, i started a 3D java game, in ~30 secs, kernel_task is killing the CPU, the game plays at 5-6 FPS.

Booted Windows 7, started the same game. Played for 2-3 hours (multiplayer FTW ) and i noticed that Windows allows it to overheat more (the case felt much more hotter than in OS X) BUT the game worked nicely, at ~100 FPS. Continously.


So, OS X kills the CPU too fast. Maybe there is a tweak for it to allow more overheating. In Snow Leopard, it overheated slower, but the same problem. I tried CoolBook to undervolt, which apparently modifies Apple's driver for the CPU. And also disables this protection, with kernel_task. It worked nicely, but i want to have Apple software, not 3rd party. And also, it should work out-of-the-box, without additional software.


I always use it on a metal-desk.

So, i can't use it for basic stuff. Such as Twitter, Safari, Xcode, etc.

What do you think?

MacBook Air Mid 2009, Mac OS X (10.7)
  • 1. Re: MacBook Air Mid-2009 overheating in Lion.
    jason1973 Level 1 Level 1 (0 points)

    2010 Macbook Air is the same, even though Spotlight has finished indexing.

  • 2. Re: MacBook Air Mid-2009 overheating in Lion.
    andreigherghe Level 1 Level 1 (0 points)

    Anyone experiencing this?

  • 3. Re: MacBook Air Mid-2009 overheating in Lion.
    shojo123 Level 1 Level 1 (0 points)

    I have exactly the same issue.

    SMC reset didn't make it better.


    Anyone knows what 10.7.1 will bring concerning bug fixes ?

  • 4. Re: MacBook Air Mid-2009 overheating in Lion.
    Aymen Level 1 Level 1 (0 points)

    This problem is killing me !! I have the original MacBook air and it used to shout down one of the cores on Snow leopard, which is really bad ! But now in Lion, it doesn't have a limit for tempreture. I'm talking about 105 C, and when it hits this point, it shuts down the whole system. I use only skype, NOTHING ELSE. The Kernal_task freaks out, and jumps up to 170%. I'll try to use coolbook, but can't Apple just fix this freakn' problem !! It makes me hate MacBook airs !


    - Aymen

  • 5. Re: MacBook Air Mid-2009 overheating in Lion.
    Fhoenig Level 1 Level 1 (5 points)

    Same issues with my mid-2009 Air. I just downgraded to Leopard and all the issues are gone. I can even play graphics heavy games again now, while on Snow Leopard upwards the laptop choked on Skype. A lot of times I had to go back to Skype on iPhone, because the computer couldn't handle the load.


    This is a clear *** Apple!


    There are not THAT many differences between the kernels I would assume. Did they not test this? Does anyone remember Apple saying "do not install on Macbook Air" on Snow Leopard?


    Apple: fix this!

  • 6. Re: MacBook Air Mid-2009 overheating in Lion.
    On_jtharpe Level 1 Level 1 (0 points)

    I have this same issue has anyone found a fix for this?

  • 7. Re: MacBook Air Mid-2009 overheating in Lion.
    Zane81 Level 1 Level 1 (0 points)

    Hi I am also suffering this problem, the Macbook Pro Feb 2010


      Model Name:          MacBook Pro

      Model Identifier:          MacBookPro5,5

      Processor Name:          Intel Core 2 Duo

      Processor Speed:          2.26 GHz

      Number of Processors:          1

      Total Number of Cores:          2

      L2 Cache:          3 MB

      Memory:          4 GB

      Bus Speed:          1.07 GHz

      Boot ROM Version:          MBP55.00AC.B03

      SMC Version (system):          1.47f2


    I installed Lion via an upgrade the first day it was released and found it really slowed my system down, so I did a clean install this week and have been monitoring and found it's the same, the kernel uses 400MB RAM, the fans run hot and the beach ball appears. Trying to use Aperture is painful it takes ages to load images now. I cleared off 80GB of storage from my hard drive in case this was causing an issue but no luck.


    Any help is greatly appreciated!

  • 8. Re: MacBook Air Mid-2009 overheating in Lion.
    Kurtz25 Level 1 Level 1 (0 points)

    Mid-2009, 2.13GHz, SSD. Exactly the same issue. It's actually rendered my computer useless.


    I may try a downgrade to Leopard. I think that was the last time this thing worked right.

  • 9. Re: MacBook Air Mid-2009 overheating in Lion.
    Zane81 Level 1 Level 1 (0 points)

    Hi, ok I seem to have improved my system significantly by opening disk manager, selecting the Macintosh HD, choosing check system permissions, then clicking repair, once this was complete I found the OS to be much the same as Snow Leopard.


    It seems even after performing a clean install, importing files and applications from Time Machine has an impact on various permissions which were causing the speed issue for me.

  • 10. Re: MacBook Air Mid-2009 overheating in Lion.
    Kurtz25 Level 1 Level 1 (0 points)

    Giving it a shot...


    Aaaaaand the fan is running full-tilt now. Oh well.


    Actually, none of that should matter anyway, since the heat issue comes up even when there is no disk activity and it's just sitting there on the desk.

  • 11. Re: MacBook Air Mid-2009 overheating in Lion.
    Lowell Tuttman Level 4 Level 4 (1,345 points)

    I just suggested to another user with this problem that I solved my heat issue by resetting both the SMC and the PRAM on my macair 11. Havent had the problem since. You will need to look up the correct keystroke combos for the macair in regular apple support, but that fix worked for me. Worth a try as it wont hurt anything even if it doesnt work.

  • 12. Re: MacBook Air Mid-2009 overheating in Lion.
    Fhoenig Level 1 Level 1 (5 points)

    The issue is not related to SMC or anything like that. The driver for Intel SpeedStep and the voltage / clock-rate management has changed after Leopard and probably again for Lion. When the CPU gets to hot, it shuts down one core to protect itself from permanent damage. When this happens, you will see the kernel_task running at high percentages.


    Apparently, you can purchase a third-part app like Coolbook and go through an iterative process to find out how low you can power your CPU at individual clock rates without causing errors in computation (system crash). As each CPU has different qualities (each as in: every one who is reading this has differrent one), you'll have to do it yourself.


    I haven't tried this myself so I do not know whether it's a working solution.


    In my Windows times I would have started to tweak this immediately. But you know what? I got used to paying the extra premium for the Apple products which usually do not require this.


    My 2009 Air was only a few months old when Snow Leopard came out (August 28, 2009).


    Apple, how can you release a an OS that skrews up same-year hardware that you sold at ~$2000 ?




    1. Buy the 2011 Macbook Air and throw out the old one?
    2. Downgrade to Leopard (which I did) and not be able to the latest version of Xcode (***** for developers)
    3. Mess around with changing the voltage of your CPU (kills the Apple hands-off spirit)


    Btw, if you downgrade to Leopard, like I did, you can even play 3D games again. Clearly it's not the hardward then...


    Surely, a public company needs to show growing revenue. Now it appears to impact its customers by forcing them to buy a new computer when not needed.


    <Edited by Host>

  • 13. Re: MacBook Air Mid-2009 overheating in Lion.
    andreigherghe Level 1 Level 1 (0 points)

    You are soooo right

    I'll take it to an  store. I saw on the internet, that  is sometimes applying too much thermal paste. And maybe they could re-apply it. For free, i hope, because i paid 2000$ for it...

  • 14. Re: MacBook Air Mid-2009 overheating in Lion.
    shojo123 Level 1 Level 1 (0 points)

    For those who are interested. I just get my MBA (2009) back from the Apple Store (genius bar). My MBA works with Snow Leopard and the temperature grows even I browse little websites...


    Their diagnositc: eveything is ok (stress test, cpu fan, thermal past...) They changed the fan to be sure.

    The genius said "if the problem still occurs, take another appointment". So... I will take another one.



    For now, I used SMC Fan control and I set the maximum fan speed @3000 rpm. It makes me crazy to hear that loud sound eveytime. Coolbook is a piece of crap since when you underclock your MBA, it becomes unusable.

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