Archive for the ‘widget’ Category

MacBook Pro temperature when running native OS X (Snow Leopard)

Wednesday, April 21st, 2010


  • After half an hour or so, the MacBook Pro base (top and bottom) tends to feel hotter than I’d expect, and I worried whether the innards were getting broiled or fried.  Having no previous experience to go by, some investigation was needed.  Various forums have some people claiming this is normal while others worry about the temperatures.


  • Downloaded iStat, a free widget for the Mac dashboard, that displays temperatures and fan speeds.  There are several temperature sensors and two fans.
  • Download site:
  • It looks and works (as far as I can tell) really good.  Also reports things like network traffic, which I also like to know about.


  • Despite the case feel, the internal temperatures were not too bad, typically around 65C though sometimes the CPU & GPU rose to 81C, which I think is the upper sensible limit.  At this speed, one of the fans speeds up a bit e.g. 2300 rpm as compared to 2000 typically.
  • A colleague (Matt Roberts) said chips are designed OK up to say 90C and higher, though connections can break down at around 120C.
  • Seems all within tolerance then, no need to worry.