1 Reply Latest reply: Dec 12, 2012 4:32 PM by Grant Bennet-Alder
chBapple Level 1 (0 points)

My Mac Pro has begun freezing at random times while at the same time the fan kicks into extremely loud high speed.  Can restart by holding down start button, but restart does not always succeed without the same problem.  Other times, restart goes fine, then I work, sometimes for lengthy time, before the freezing problem with lohigh speed fan.

Mac Pro (Early 2008), Mac OS X (10.7.5)
  • Grant Bennet-Alder Level 9 (55,250 points)

    The initial fan speed is set to maximum by Hardware at power-on. Then the software resets those to more moderate speed several times a second based on actual temperature readings.


    If your computer stops running the software normally, the fan speeds will not get reset and Hardware will revert the fan speed to maximum to avoid thermal damage to your computer. There is no additional information there except that the software is not running normally.


    If there was a kernel panic, those are saved in logs and can be read out and examined for clues about the failure. This article show how to get them out, and you can just cut and paste them here for Readers to look at for clues, or take them to the Genius Bar.


    Mac OS X: How to log a kernel panic