I have noticed that fan speed on my Mac is 499 rpm. Now this is a computer with installed OSX El Capitan, Xcode 8.2.1... I have noticed this when Xcode got crashed few weeks ago (the information was provided in Xcode crash log). Now, today, when it crashed again, I have noticed the same fan speed, which is 499...That is a bit odd I must say, because rpm are very low, and I got same number twice.

I wonder is this accurate info actually and what is the normal fan speed for MacPro3,1?

1 Answer 1


There is no "normal" speed for a fan in a computer. The fan spins at a speed necessary to keep the CPU temp in the "normal operating range."1

For your particular Mac, the maximum operating temperature is about 82°C (180°F). However, keep in mind that this does not factor in other components like heat from drives, adapters, etc. which may also go into calculating when a fan is engaged.

1 See section 5 in Intel® Xeon® Processor E5-2400 Product Family Thermal/Mechanical Design Guide May 2012

  • I was looking for an explanation why I always get 499 in the crash log actually...I suspect that what I am seeing in a crash log is not a real fan state. That's why I asked the question.
    – Whirlwind
    Mar 22, 2017 at 15:13
  • That "499" is a calculated value not an actual speed based on voltage sent by the SMC to the fan.
    – Allan
    Mar 22, 2017 at 15:46
  • Okay, that at least explains something...
    – Whirlwind
    Mar 22, 2017 at 15:49
  • Also, 499 is the minimum RPM for some of the fans in a tower Mac Pro. Unless you are doing some very heavy lifting (video editing, rendering, etc), it's highly likely your fan speed is between 498 and 501.
    – NoahL
    Mar 22, 2017 at 21:16

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