[Ti] Heat and 17"

[Kynan Shook]

FWIW, the 15" TiBook (at least the latest revision, but probably all of 
them) has a similar sleep point at 85 degrees C.  The 12" probably has 
a similar setting, but it's not mentioned in the developer docs.  Every 
Mac, however, uses the same PMU (Power Management Unit), known as the 
PMU99.  Each computer has its own specific power-saving features 
though, ranging from running only one processor on a dual-G4 to reduced 
speed or disabling caches on the PowerBook.
I have yet to see or hear of a PowerBook going to sleep due to 
excessive heat, however; it is likely that this happening would be a 
hardware problem.  I have, however, witnessed a number of desktops and 
some laptops that act very flaky as they heat up: the hotter a 
processor gets, the slower it runs, possibly eventually getting to the 
point where the processor isn't capable of running at it's normal speed 
any more, so it crashes the computer by giving incorrect results to 
operations.

David Ferleger <david at ferleger.com> writes:
> Thought this may be of interest to those who think/feel about
> heat, powerbooks, the 15" and the 17" -- from the newly
> released Developer Note for the 17" AL PB
>
> ''
> The PowerBook G4 17-inch computer has a variable speed fan control
> circuit and a thermal circuit that will force the unit into
> reduce-processor mode at 72 degrees Celsius and into sleep mode if the
> processor temperature exceeds 79 degrees Celsius.   "


Kynan Shook
kshook at mac.com
http://homepage.mac.com/kshook/index.html