power efficiency

[richard.pieri-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Richard Pieri)]

On Nov 24, 2009, at 6:31 PM, Richard Pieri wrote:
> That said, Apple does run the fans at lower speeds than one might expect, so the notebooks run a bit hot.  Not unduly so; temperatures do remain within tolerances for the hardware.  So they do run hot under load.  The lower base fan speeds make a noticeable difference in battery life and noise level -- the two reasons Apple does it that way.

Just as a data point, I'm currently running a video encode on my MacBook Pro (Early 2008/Penryn).  iStat Pro says that the CPU temp is 78C.  The maximum operating temperature for the CPU is 95C so that's well within tolerances.

Apple uses a lot more metal than other manufacturers in the casings (even in the polycarbonate-hulled MacBooks) and all that metal draws a lot of heat away from the main board.  This is good because radiant cooling of the electronics is cheaper than running fans, but it does mean that MacBooks are warmer to the touch than the competition.

--Rich P.