MacBook Pro Temperature Monitor

MacBook Pro Temperature Monitor

Summary: There is now a way to read the internal temperature of the MacBook Pro, something no other software has been able to do to date.


speedit.jpgThere is now a way to read the internal temperature of the MacBook Pro, something no other software has been able to do to date. A creative developer has figured out a way to get data from the internal monitors via a kernel extension (kext).

To install the "speedit" kernel extension:

1. Download the speedit DMG from (direct download, mirror).

2. Mount the DMG and move the speedit.kext to your user folder.

3. Start Terminal (/Applications/Utilities/Terminal)

4. Terminal should drop you in your home directory by default:


If not, move to the directory that contains "speedit.kext" using the cd command. For example:

    % cd /Users/admin/Projects/Speedit
5. Once there, use the ls command to view the contents of this directory and confirm that the speedit.kext is there. For example:    

    % ls

6. If it's there, type:
    sudo chown -R root:wheel speedit.kext

7. After Terminal lectures you about security, enter your admin password

8. Then enter:

    sudo kextload -v speedit.kext

If all went well, you should see this message:

    kextload: speedit.kext loaded successfully
Once the kext is loaded you can enter this command to get the temperature in Celsius:

    sysctl kern.cpu_temp    

There are other commands that you can run (they're in the README.txt file), but none of them seemed to give any results on my MacBook Pro 2.0GHz. You can report errors to the InCrew forums.

Interrupting Moss from the SomethingAwful forums reports that after reapplying the thermal grease on his MBP he gets temperature readings of:

    48C idle     64C at 100% on both cores (while encoding a DVD.)
Others with the original thermal grease application are reporting temperatures as high as:

    65C idle    85C at 100% on both cores

One user is reporting:
    71C idle    95C under full load

(All we need now is for some enterprising developer to hack this thing into a neat little application that will display this information in a tiny appliation (NOT a dashboard widget, please!) or even better a small menu bar item. - Any takers?)

If you try the speedit kext on your MacBook Pro, please post your results in the TalkBack below!


Topic: Apps

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  • this is cool - I wrote a wrapper for this tool

    Nice find. I wrote a little wrapper for this tool that seems to work. I
    need a cool icon for the big "refesh" button though. Drop me a note
    if you want it (or maybe I'll just release it).

    • Release request

      If you wouldn't mind releasing your wrapper, I would greatly appreciate it.

      Thank you.
      • Released

        As requested ( Note that this is just a really quick app I
        threw together in no time. It's a wrapper around the command
        line. There's no error checking and no timer :). It takes the
        output of
        sysctl kern.cpu_temp
        gets the value, converts it to Faherenheit, and displays. Rather
        than write a timer, I threw in a date field so you know the last
        time you checked.

        Someone mentioned this (
        TemperatureMonitor.html) which is very slick and needs the
        kernel extension but does much more than run a command and
        parse the text.

  • Link to app that does this?

    Doesn't this application already do this without any tweaking?
    • No, that app needs this kernel extension

      The new version of Temperature Monitor just released can detect if
      you have the extension installed and can use it to get readings.

      But you still have to install the extension first.

      Before this version, it was not able to get temperature readings on
  • 70 while web browsing

    I thought thie thing was hotter then it should be. Now I just need to
    convince Apple that 70 while under light load is too much.
  • Is that number right?

    So I loaded the program and ran per instructions. I was getting
    readings of 24-26 early on.

    I ran a few processor intensive programs on my MBP and am
    now getting 32-34

    Meanwhile, its so hot I can barely hold it.

    I already got a blister from it once!

    2.16 GHz / 1GB / 120GB / W861--- serial run
  • speedit on MacBook Pro

    Yikes! Three terminal windows going, two running while true do
    x=1 done shell script, the other checking kern.cpu_temp using
    speedit every 5 seconds. It got up to 94 (that's degrees C) and the
    fans came on, now it's settled down to 88 or 90. This is WAY HOT.
    The underside of the MBP (2.0GHz) can barely be touched. CPU
    running at 100% according to Activity Monitor. I killed both shell
    scripts and the monitor rapidly dropped (within seconds) to 65 and
    the fans have stopped.
  • 59 web browsing

    it'd be nice if the fans would kick on!
  • 58 - 60 Max temp at Max Load

    I've been running the System Load utility to max both processors
    out at 100% to check this out. After one hour of running the
    CPUs at 100% utilization, I haven't seen a temperature spike over
    60 degress C.

    This is a 3 day old MacBok Pro 15" with the 7200 RPM hard drive
    and 2.16 gigahertz processor.

    I can live with 60-C since that's less than 2/3 the redline on the
    CPU. The aluminum case does feel warm next to the mousepad,
    and almost hot on my legs if I hold it on my lap. I put an
    outdoor air temp thermometer under the case and it showed
    38-C...just a touch warmer than normal human body temp.

    Not hot enough to take apart the machine and risk breaking it to
    apply better thermal grease (Silver5 seems to be the best).
    • Forgot to mention fan noise....

      Forgot to mention that I haven't heard the fan come on on this
      thing once since I purchased it...
  • A hack for keeping your MacTel cool...

    See here for a hack that woks. My MacBook Pro 2.0 GHz was running very hot, too hot to touch at times. After trying to find a temp monitor that worked I managed to get CoreDuo Temp to work and it sits nicely on the top of my screen telling me the temp of my cpu. After following the hack outlined above my cpu runs @ 20-25 degrees C, much cooler than before.
  • RE: MacBook Pro Temperature Monitor

    This mod does not work on Mac OSX 10.4.11
  • RE: MacBook Pro Temperature Monitor

    iStat Nano is a much cleaner way to do this.