[RC5] RC5 on laptops & CPU temperature

Elektron elektron_rc5 at yahoo.ca
Fri Nov 5 05:52:10 EST 2004

> Laptop coolings solutions have less marginal for safety in 100% CPU 
> utilization operation, but if the thing is in working order, it should 
> not cause any problems (cleaning of the heatsink with a vacuum cleaner 
> or a can of compressed air might be needed). If you are worried about 
> the increase in the surface temperature, you could place the laptop, 
> with the lid open, centered on a metal surface covering just 1/3 of 
> the width (like the top of a tower desk machine chassis). The cooling 
> fan and the CPU socket is usually to the side of the laptop, so this 
> arrangement ensures minimum cooling air inflow resistance and also 
> makes sure hot parts don't damage the surface below (unless the top of 
> your tower is made from soft plastic...).

This depends on what the bottom of your laptop is made of. The bottom 
of my iBook is plastic, and it does get quite warm (though not 
uncomfortably warm, which is a good thing). Open-air cooling of the 
underside isn't that much better than none at all, though. But if you 
want it to run much cooler, levitate it and get a fan to blow air 
across it (a 50mm fan should be plenty). This works pretty well for my 
external hard disk, though it requires the case open and the hard disk 
upside-down and the fan sitting roughly on the spindle.

> IIRC the temperature monitoring and pausing works only in Apple G3 and 
> G4 laptops. If you worry about the noise of the fan, you could use a 
> task scheduler to run "dnetc.com -pause" and "dnetc.com -unpause" in a 
> few minute intervals.

It should also be possible to write a program to monitor the CPU 
temperature (there are plenty of these) and rename the pausefile.

- Purr

More information about the rc5 mailing list