hi folks,
thanks for all the responses regarding my Frodo-style
cpu-slaying with prime95!
Mary, it's great that your dell laptop throttles back the cpu when it
overheats. that's smarter than my P4 desktop with Asus motherboard,
and also smarter than the toshiba 'satellite' laptop. if you
watch/compare the iteration time of prime95 that ought to indicate
when the cpu is throttled back... when the toshiba laptop was on its
last-leg i put it in the 50 degree garage so it could keep computing.
i'm sorely tempted to do that again now with the working fan but i
must restrain myself! maybe i need a mantra or theme song to help.
sing this to the mickey mouse club theme: "FFT, GCD, M-O-U-S-E". or
maybe FFT, GCD, G-E-O-R-G! well, almost. maybe this sort of thing a
bit too far out there for you prime readers! ok, i'll try to throttle
back my juvenile sense of humor a bit...
> Yes, I do not think most laptops are very durable. Companies
> know they will usually get a lot less use than a desktop, so
> they know they only need to get a few months of actual runtime
> to get them out of the warranty period.
yes this point is well taken!
> I think it has more to
> do with simply using them 24/7 (or more than a few hours a day
> on average) than with prime95.
i doubt that to some extent - when most/many/some laptops are sitting
idle, or doing something simple like a realplayer audio stream, there
is no need for their cpu fan to run.
>> 3 - i also ran the prime95 app for a year or so on an ancient
>> cyrix p120+ which had a cpu-fan that stopped. after a couple
>> months of no-cpu-fan, that cpu died completely...
> Well, I don't think that necessarily has anything to do with
> prime95 either. My dad had a Cyrix 200, his cpu fan started
> being noisy and flaking out, I advised him to get a new fan,
> which he did not, and eventually the system bombed hard. He
> was not running prime95.
i hear ya...
i think that prime95 hastened the cyrix machine's departure...
the amazing part is that the machine ran for nearly a year
with no cpu fan, including through many >100 degree days.
> Thermal protection for P4's is partly a matter of the chip, and
> partly a matter of the motherboard/chipset. Intel built
> motherboards have been shown to be very paranoid about
> throttling the CPU compared to boards built by other vendors
> (and with non-Intel chipsets). As far as the CPU's own thermal
> protection, Intel took some heat for the fact that the thermal
> protection was causing performance problems compared to AMD
> chips. There was a rather famous test done by Tom's Hardware
> Guide where they removed the heatsink from test chips while
> they were running to simulate a catastrophic failure of the
> heatsink falling off the CPU. The P4 throttled perfectly with
> a huge performance degradation, but it kept going. So it does
> seem odd that your chip would have "burned", but perhaps Intel
> backed off on the thermal diodes in the chip itself because of
> the performance problems.
this is all very interesting info - thank you very much! indeed i
think thought that an Intel motherboard with the 2Ghz P4 would have
done better than the Asus motherboard. i had seen that Tom's h/w
guide review of the P4 - that's one reason why i am skeptical when the
vendor said that i had burned out my P4 chip. but the data you have
provided here has provided some new pieces to the jigsaw puzzle.
> Date: Mon, 14 Jan 2002 12:20:16 -0800 From: "Aaron Blosser"
> <[EMAIL PROTECTED]> Subject: RE: Mersenne: slaying cpus with
> prime95
> I'd wager that in most of those instances, the computer would
> have died without Prime95's help.
> Faulty CPU fans in particular... whether they conk out after a
> short while or eventually, a bad fan is a ticking time bomb.
> Prime95 may have shortened the life span a bit, but it was
> doomed. :)
hi Aaron - oh yes! have no doubt that prime95 hastened the
computer/cpu's death! but maybe the cpu only quit 3 nanoseconds
sooner than it would have without prime95 ;)
> Any machine that lacks proper ventilation and allows excess CPU
> heat to affect the hard drive is buggy design if you ask me.
from what i've seen, many laptops are this way by design. they are
too small to isolate the hard drive from the cpu heat, especially when
the cpu fan quits.
> I have a 1GHz IBM laptop that I run Prime95 on 24/7 and while
> the thing can get hot if I actually place it on my lap, I've
> had nary a problem except on a couple occasions when I
> inadvertently blocked the inflow air vent and the thing did
> overheat. When it did that, it just shut itself down.
it's pretty clear that the IBM laptop fans are more robust
than the toshiba satellite-pro... go big blue!
> Things to look for on any computer, Prime95 running or not, are
> noisy cpu/case fans or fans that don't spin at all. And if you
> have thermal monitoring, pay attention to it. Hard drives
> nowadays almost all have SMART on them, so find a program that
> can read those stats and see if your drive is giving out
> warnings. Many vendors include software for monitoring your
> system health (I know HP and Compaq do, and I think IBM does
> too but I haven't looked). There are 3rd party programs for
> all that as well.
hmm. i have not seen any hard-drive-temp-monitor tools but thank you
for the SMART pointer. i will check into that. and oh ya, i hear ya
about checking for non-spinning or noisy fans. my machines' fans
always end up noisy since i run them 24x7.
> And of course, overclocking is pushing the limits anyway, so I
> guess we shouldn't be too surprised to find that overclocking
> may ruin a CPU. I do find it curious that the thermal
> protection on your P4 didn't kick in, but perhaps your
> computer's BIOS had some default settings disabling that?
nope - not that i could see... it seemed as if the motherboard was
designed without knowledge of the latest P4 thermal protection. so
maybe the motherboard was originally designed for a slower P4 without
the thermal protection (1.5Ghz?) ? well, we might think that
it might tend to better protect the 2Ghz P4 thermally...
> Or
> it had been disabled? I dunno... I don't have a P4 machine
> (yet), so I can't say. :)
me neither, any more :| maybe by tomorrow i'll have one again.
> In short, I've killed many machines in my life... CPU fans that
i figured i would find some like-minded cpu-killers here!
> stopped working and thus frying the processor, or doing silly
> things like plugging a 486 in the wrong way, etc. And of all
> the machines I've fried, NONE were running Prime95. Heck, I
> guess I'd have to say that running Prime95 on a machine has
> actually brought me better luck with them than without. :)
i wish i could say the same!
> Aaron
> Mmm, yes the fan on my laptop (Dell 38000) sounds like someone
> dumped a load of grit in it - not good :-( I stopped running
> prime95 (mprime actually) on it for that reason.
> - -- Nick Craig-Wood [EMAIL PROTECTED]
maybe there is a monster dust-bunny in there... i couldn't figure out
how to properly open the case of my wife's laptop PC. but if i can't
resist the primal95 urge, i'll probably have to figure that out and
replace the fan myself next year!
> As others have already mentioned, those machines would probably
> have died even without Prime95. The way I have always looked at
> it, Prime95 generally causes those types of (pre-existing)
> problems to manifest _before_ the warranty expires, rather than
> after. This feature is certainly not a Bad Thing :-)
> Steve Harris
indeed, prime95 is a great "DVT tester", or at least a "DT tester".
(dvt=deviate-voltage-and-temperature, or something close to that.)
> <[EMAIL PROTECTED]> Subject: RE: Mersenne: slaying cpus with
> prime95
> Crazy thought here, but what if prime95 only ran at x% speed?
> For example, put some hlts in there and see how that affects
> the CPU temp. I think for those of us that run Prime95 on
> laptops find it unnerving when the fans are running full blast
> all the time, and it would be cool to have a cooler running
> prime95 rather than no prime95 at all.
> Thinking about it, you could probably keep the temp down to
> around normal idle temp...
this is a good thought, Jeremy. and indeed there are "cpu cooler"
programs out there which force a few occasional no-op instructions, or
some such, in order to keep the cpu temp lower. i suppose i could try
this if i try to put my wife's computer on
on the other hand a cpu-cooler-program is contrary to my raison-d'etre
for my own PCs - keeping every-spare-cycle in use for prime95! if the
PCs can't take the prime95 heat, it's just a form of computational
natural selection...
/eli
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