On Fri, May 11, 2007 at 07:18:25PM +0000, Pavel Machek wrote: > 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.
I tend to believe that. I've slowed down the FANs on my dual-athlon XP to silent them, and I found the system to be (apparently) stable till 96 deg Celsius with FANs unplugged. So I regulated them in order to maintain a temperature below 90 deg for a safety margin, and they seem to be as happy as my ears. They've been like that for the last 3-4 years, I don't remember. On a related note, older technology is less sensible. My old VAX VLC4000 from 1991 which received a small heatsink in exchange for its noisy fans is still doing well in an closed place. I'm more worried for the EPROMs which store the boot code. Also, I think that the RS6000 processed at half-micron which run the Mars rovers might run for hundreds of years at 30 MHz. > (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... even at 60, many of them die within a few years. Bu I think we're "slightly" off-topic now... > Pavel Cheers Willy - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/