Monitoring the heat output on a PowerBook?

Discussion in 'Mac Apps and Mac App Store' started by Jennifer, Jun 15, 2004.

  1. Jennifer macrumors member

    Feb 20, 2004
    I was wondering if anyone knew of a freeware or other application that will track/monitor the heat output on the PowerBook (G4, 1GHz)? I've heard of PC apps that will do just that. How about for the Mac?

    Thanks for your input,
  2. Chip NoVaMac macrumors G3

    Chip NoVaMac

    Dec 25, 2003
    Northern Virginia
    Konfabulator has Temperature Text applet.

    My question is what is the normal and safe operating temperature of the PB 12" 1ghz model?
  3. aStabell macrumors member


    Jan 1, 2004
    How exactly does this program monitor the heat output? Or does it just do a calculation of how hard the cpu is working?
  4. Jennifer thread starter macrumors member

    Feb 20, 2004
    "Temperature Monitor" works well and answers other Qs

    Thank you both for recommending "Temperature Monitor."

    Now to give back to the community: Here's an exerpt from the "Temperature Monitor" literature that I think will answer both of the further questions. You can also go to the website.

    How does the program measure the CPU temperature?

    There are two cases to distinguish here:

    a) You have a Macintosh system with an "older" PowerPC processor,

    b) you have a machine with a PowerPC 7450 or later processor.

    In case (a), temperature measurements are based on a component inside the processor itself, known as "Thermal Assist Unit (TAU)". This unit uses a physical effect in the PowerPC processor to guess the current temperature directly at the die-junction, the connection between the silicon chip and the ceramic base. Unfortunately, this technique is very unreliable, depending on CPU load and other circumstances: Measured values can fluctuate very rapidly and can generally be off by 12 degrees Celsius (21,6 degrees Fahrenheit). For those reasons, Motorola has disabled the Thermal Assist Unit on the PPC 7450 and later processors.

    In case no TAU is available (b), Temperature Monitor will look for a sensor built into your computer to get its temperature values. Apple has equipped all the latest Macintosh models that require intensive cooling with their own sensors, essentially to control the built-in fans and prevent overheating. Those sensors are very reliable and much more accurate than the TAU-based solution.

    If your computer has a PPC 7450 or later but no temperature sensor was built in, no measuring is possible.

    What is the "normal" temperature for current CPUs?

    This depends on the particular model, but CPU temperatures between 122 and 158 degrees Fahrenheit (50 to 70 degrees Celsius) can be expected for all up-to-date computers. Some specification values for G4 processors used in the MDD and FW800 models are given by the following table. Note that the official temperature limits are defined for measuring at the die junction. The Macintosh temperature sensors are not at the CPU die itself and are not in contact with the heat sink which means the measured temperature may be higher than the die junction temperature.
  5. Biker21098 macrumors member

    Aug 13, 2002
    wow, good to know stuff

    Glad someone actually reads the README and checks up on the apps they download. Way to go. I know my 15in ALbook gets pretty hot, hottest yet was about 148F usually under stressed load it run from 139-145F going back and forth as the fan turns on and off. I have it on a stand that has two USB fans as well.
  6. Jennifer thread starter macrumors member

    Feb 20, 2004
    More Information on PowerBook Processor Please . . .

    Thanks! And no problem. Happy to be of help.

    Here's a further question: Can anyone give me more information or help to dechiper the below information? It is supposed to be a more precise chart of min/max temps for the different Mac and PC processors with G4 CPU model, Macintosh model, temperature variables. I have a PowerBook 1 GHz, PowerPC G4. Which does my unit correspond to in the chart below?


    MDD 867 / 1000 MHz
    65° C / 149° F

    75° C / 167° F

    105° C / 221° F

    65° C / 149° F

    65° C / 149° F

    most other G4 models
    105° C / 221° F

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