0ne_Up wrote:
> Hi,
> I was just browsing the Motherboard Monitor 5 settings, when I
> spotted the following crazy option: 'low temperature warning'.
> This sounds weird to me, I always thought 'the colder the better!' Can
> anyone explain this???
IIRC, if you get the chip really cold (-50 deg C or so) the conductivity of
the die (though not the interconnet of course) has dropped down
significantly compared to when it's at room temperature. This results in
instability as the transistors can no longer switch fast enough. The problem
first occurs in rarely used parts of the chips (which don't produce so much
heat, so are cooler than the "die" temperature). People running recharged
phase-change systems often have a "minimum" temperature set on the
compressor control, and have reported instability if the chips get too cold
(though more voltage usually fixes things
).
A bigger problem is due to mechanical issues. The colder you get the CPU,
the more brittle it gets, and hence the more susceptible to hairline cracks
from vibration (from compressors, etc). This especially applies to solder
joints, though these are fairly minimal on the CPU itself. This obviously
isn't an immediate effect, but it does shorten the lifespan of the device
unless significant care is taken to avoid vibrations. Also, the chip is made
of many different materials each with different temperature coefficients of
expansion. So as the chip is cooled, different parts of the chip change size
at different rates, resulting in increased mechanical stress on the chip. I
don't think this latter one is very bad, though I'm open to corrections
Finally, you get problems with things around the CPU if you run it cold
enough. I'm not sure what motherboard manufacturers use nowadays, but most
electrolytic capacitors (the big ones) used to have water-based dielectrics
in them. Cool them down sufficiently and the dielectrics would freeze, with
a similar effect to leaving a bottle of water in the freezer too long. This
may not apply to modern boards. Finally, if your board is getting quite
cold, then you increase the risk of solder failure as mentioned above.
--
Michael Brown
<a style='text-decoration: underline;' href="http://www.emboss.co.nz" target="_blank">www.emboss.co.nz</a> : OOS/RSI software and more
Add michael@ to emboss.co.nz - My inbox is always open<!-- ~MESSAGE_AFTER~ -->
>> Stay informed about: motherboard monitor 
FAQ
Profile
Private Messages
Log in
