Fans and Temperatures

Discussion in 'MacBook Air' started by RobertI, Apr 13, 2009.

  1. RobertI macrumors newbie

    Apr 13, 2009
    Edinburgh, Scotland
    I got a Macbook Air just before Christmas --- an "early 2008" model
    with 80GByte disk drive and mini-DVI connector.

    Now I'm starting to use it in anger, I'm noticing that the fan is
    running an awful lot. Even when it is standing on a hard surface in a
    cool room.

    Using iStat, I'm finding that he machine "idles" at 50-ish degrees,
    fans pretty well silent at 2500rpm. BUT if it is doing almost
    anything at all, the temperature goes up to around 70, fans at 6200.

    Just looking at a web page with a Flash advert on one side
    is enough. Neither "top" nor "Activity Monitor" show any interesting
    level of CPU activity, but the fan is soon whirring for all its worth.

    I've seen various people talking about problems with the thermal
    gunk between the CPU and the heat sink, and I'm wondering if I have

    But here's the thing I've just noticed: iStat is reporting the
    heat sink temperature fully 13 degrees below the CPU temperature.
    So this second, 64 versus 51.

    Is this normal?

    Can anyone tell me the temperature difference that they are seeing
    between CPU A and Heat Sink A?

    Thanks in advance.

  2. darngooddesign macrumors G3

    Jul 4, 2007
    Atlanta, GA
    By the time you purchased your Rev A there was plenty of evidence that Flash (videos are most culprit) in websites taxes the system hard. That's just the nature of the beast.

    As far as what other people are getting, that depends on what they are doing.

    You need to be very specific about what task you are doing otherwise a comparison is worthless.
  3. RobertI thread starter macrumors newbie

    Apr 13, 2009
    Edinburgh, Scotland
    Temperature DIFFERENCES...

    Thanks for the comment, Darngooddesign.

    You are of course right about only getting valid CPU temperature
    comparisons if I am specific about the load on the machine.

    (FWIW, I believe I have closed down everything except the
    Firefox windows on GMail and Google Calendar, and I'M *STILL*
    at 63 degrees and 5800 RPM)

    But it's the temperature difference between CPU and heat sink
    that I'm interested in.

    Whatever the load on the machine, should CPU A (apparently)
    be 13 degrees hotter than the heatsink A? Or is that a sign of
    bad thermal contact between them?

  4. Scottsdale macrumors 601


    Sep 19, 2008
    You obviously know the original MBA has many problems. You could ask Apple to upgrade it to the new model, but they probably will not do that. Although I have read that many original MBA owners got free upgrades to the rev B after their original MBA had so many problems.

    So, unless you want to upgrade, you need to address the two most common solutions. Remove and reapply the thermal paste and install Cool Book which will set you back less than $20 for both.

    I had an original MBA, and it suffered from the common problems. I sold it without trying thermal paste or Cool Book. But I have read how many people have used both options to make their original MBA run a lot cooler and stop suffering from overheating, core shutdown, and completely locking up.

    I would say if you're willing to take your MBA apart and deal with the thermal paste issue, and you're willing to undervolt your MBA with Cool Book, you just might make your MBA work without all of the problems.

    Good luck.
  5. aleksandra. macrumors 6502a

    Sep 13, 2008
    Warsaw, Poland
    Heat Sink A? Am I supposed to see it in iStat Pro along with CPU temperature? My Air is rev. B, but iStat reports only the following (I've checked display preferences for others, there're none): CPU A, Airport, Enclosure Base 1, 2 & 3, Power Supply 1 & 2. What version of iStat are you using?
  6. darngooddesign macrumors G3

    Jul 4, 2007
    Atlanta, GA
    FWIW I have a unibody MBP and there is a 5-6 deg difference between the CPU and GPU heatsink at idle with the former being hotter.
  7. aaquib macrumors 65816


    Sep 11, 2007
    Toronto, Canada
    First, purchase CoolBook. it's a $10, yet very useful software.

    Next, download SMCFanControl. Then, use the attached Automator file to limit your fan speed to 4000RPM.

    Attached Files:

  8. gcmexico macrumors 6502a


    Dec 22, 2007
    New York City
    is it dangerous to control the fans? I might install this, just want some more info
  9. TheRiseofTheFal macrumors regular


    May 9, 2008
    just curious where have you seen people receiving free upgrades? i have had terrible problems with my heat and fans, but would that warrant an upgrade from apple? i would love to know how this was done, but i'm not holding out that I will fall in the same boat just curious
  10. michael.lauden macrumors 68020


    Dec 25, 2008
    it's only dangerous if you change the minimum fan speed at higher temperatures.

    or if you disable the fans. but the software i used (not SMC) wouldn't allow you to go under factory presets,

    you could only increase the fan speed up until the factory preset of whatever RPM is at the highest temp

    but i'm sure if you had fans spinning at 10,000RPM 24/7 it wouldn't be a good thing either.
  11. RobertI thread starter macrumors newbie

    Apr 13, 2009
    Edinburgh, Scotland
    iStat version 1.3, which reports on CPU A, Airport Card, Battery 0, Enclosure Bottom, Enclosure Bottom 2, Enclosure Bottom 3, Heatsink A, Power Supply 1 and Macintosh HD.
  12. turugara macrumors regular

    Jan 18, 2009
    CPU A: 60
    Heatsink A: 53

    Arctic Silver MX-2
    Coolbook undervolting.
  13. riveting macrumors 6502

    Mar 11, 2009
    Can you tell me where do you find the automator file? Can I change 4000 to sth. else like 4500?

    I'v been really annoyed with the fan noise of mine and looking for a fan control software, but apparently SMC fan control does nothing but change the minimum fan speed.

  14. GeekGirl* macrumors 65816


    Feb 26, 2009
    Buffalo, NY
    Mine a A stays between 45-57 with no fan noise at all.
  15. riveting macrumors 6502

    Mar 11, 2009
    Can somebody confirm that this automator file is good? Some one explain how to use it?

    The coolbook thing isn't helping at all, it may reduce the maximum temperature when I am watching moive, but it seems to make the fan ramp up even more than usual. I really need a fan control type of software. Thanks.

  16. ppc750fx macrumors 65816

    Aug 20, 2008
    No, CoolBook does work. It might not fix the problem entirely, but it will let you undervolt the processor, which in turn will lower its thermal output.
  17. zsnow macrumors regular

    Mar 15, 2009
    I did apply the as5 thermal paste today. Didn't notice much difference compare with the original paste.
    Here is what i got.
    When watching 720p mkv movies. CPU Temp Max: 70C Fan:6200rpm Heatsink:59C. The temp drop under 50 in 1 min, the fan drop to 2500rpm in aroudn 4 min.

    When idle(while i'm typing this): CPU Temp: 47C Fan:2500rpm Heatsink:44C

    Watching Youtube HQ fullscreen for 10min. CPU Temp:67C Fan:6200rpm, Heatsink 57C.

    Refurb RevA air
  18. GeekGirl* macrumors 65816


    Feb 26, 2009
    Buffalo, NY
    The funny thing is seems like the first ones were bad, I bought a A refurb and I am not having any problems at all like the very first one.

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