[mythtv-users] OT: CPU temperatures

[Maarten]

On Sunday 31 October 2004 20:48, Adam Felson wrote:
> You're overcautious.  Anything under 70 DEG C is fine and frankly 70-75
> DEG C is nothing to worry about.

Yeah well, I beg to differ... because of a.o. the following points:

* Reported temperature may not be quite accurate to true temp. It can even be 
FAR off, depending on how and where it is measured (IN-die, external, ...).
An ambient temperature is entirely different than die-temperature. And can you 
be certain the temp you're reading is measured where you think it is ?
* Silicon ages way faster with elevated temperatures. It could easily halve, 
or much worse, the life expectancy of components. Thus, cooler==better.
But you may say "oh well, in 18 months I'll have a new system anyway", sure. 
* Hot components may show unexpected results, not failures but 
miscalculations, instabilities and things of the sort.  I'm not saying they 
do per se, but they might. Very very difficult to track that sort of bugs.
* What happens if you run your unattended-24x7 mythtv box @70 C and your airco 
dies / there is a sudden heatwave ? Bye bye mythtv box... fried for sure.
You need to allow for special external circumstances, thus the need for some 
buffer zone or tolerance or whatever you may call it. 10C seems reasonable.

Case in point, remember the IBM drives that were flaky ? And in the end IBM 
specified them as "desktop drives, not to be used longer than 8 hours a day"?
That was a clear-cut case of being especially sensitive to high(er) temp 
environments.  I have had several of those drives and not a single one of 
them have died, just because they were in a *really* well cooled server. (In 
fact they remained *cold* to the touch, that's how well cooled they were...)

Higher-than-normal temperatures are not good for humans, and aren't great for 
computers either.  Do you work just as hard and efficient as usual when the 
airco is off ?  Well, computers show similar behaviour. They *will* operate 
@70C, but they do not like it. (or maybe you were talking about fahrenheit?) 
Same goes for combustion engines.  They fact that they can go up to a real 
high RPM does not mean they encourage you to drive on the interstate in third 
gear. But sure, they can and will if you just want (push) them hard enough.

So no, I really don't feel I'm being overcautious.  But YMMV.

Maarten

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