Archived from groups: alt.comp.hardware.overclocking (
More info?)
And someone would cool his system to -200c with Liquid Nitrogen...
"Michael Brown" <see@signature.below> schreef in bericht
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rqad.12164$JQ4.761871@news.xtra.co.nz...
> 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
> www.emboss.co.nz : OOS/RSI software and more
> Add michael@ to emboss.co.nz - My inbox is always open
>
>