Re: [patch] CFS scheduler, -v8

Pavel Machek
2007-05-11T19:21:33Z

Hi!

> > Also notice that current cpus were not designed to work 300 years.
> > When we have hw designed for 50 years+, we can start to worry.
>
> Indeed. CPU manufacturers don't seem to talk about it very much, and
> searching for it with google on intel.com comes up with
>
> The failure rate and Mean Time Between Failure (MTBF) data is not
> currently available on our website. You may contact Intel?
> Customer Support for this information.
>
> which seems to be just a fancy way of saying "we don't actually want to
> talk about it". Probably not because it's actually all that bad, but
> simply because people don't think about it, and there's no reason a CPU
> manufacturer would *want* people to think about it.
>
> But if you wondered why server CPU's usually run at a lower frequency,
> it's because of MTBF issues. I think a desktop CPU is usually specced to
> run for 5 years (and that's expecting that it's turned off or at least
> idle much of the time), while a server CPU is expected to last longer and
> be active a much bigger percentage of time.
>
> ("Active" == "heat" == "more damage due to atom migration etc". Which is
> part of why you're not supposed to overclock stuff: it may well work well
> for you, but for all you know it will cut your expected CPU life by 90%).

Actually, when I talked with AMD, they told me that cpus should last
10 years *at their max specced temperature*... which is 95Celsius. So
overclocking is not that evil, according to my info.

(That would mean way more than 10 years if you use your cpu
'normally'.)

But I guess capacitors from cpu power supply will hate you running cpu
at 95C...
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html