Re: [PATCH] Acer Aspire One Fan Control

From: Peter Feuerer
Date: Tue Apr 28 2009 - 16:17:48 EST


Hi Maxim,

Their N270 datasheet
(http://download.intel.com/design/processor/datashts/320032.pdf) talks
about max Tj (junction temperature) being 90ÂC for a TDP of 2.5W and if
you operate below that limit "functionality and long-term reliability
can be expected." :)

There's also an internal termtrip sensor which is designed to go off at
Tj=125ÂC so, yeah, I guess something 70ÂC should be ok.

I have small note:

So yes cpu can withstand 90 C, but will rest of the motherboard?

(Most other cpus are rated at 60C)

That's why the module is started in "user mode" where the bios controls the fan. - The Bios just starts the fan as soon as the temperature is higher than 40 degree celsius.

The user must explicitely start "kernel mode" to make the kernel controlling the fan. Maybe we should add a warning somewhere, that it could harm the hardware?

regards,
--peter
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