🚀 go-pugleaf

In article <OTTO.90Dec31040234@tukki.jyu.fi> otto@tukki.jyu.fi (Otto J. Makela) writes:
>In article <1990Dec28.210731.10685@zoo.toronto.edu> henry@zoo.toronto.edu (Henry Spencer) writes:
>   In article <1990Dec18.234020.2491@uoft02.utoledo.edu> stx0641@uoft02.utoledo.edu writes:
>   >	My friend told me that we can use 16Mhz 80386 DX CPU on 25Mhz 80386 DX
>   >motherboard.  Is it reliable?  Will it destroyed chips on the motherboard?
>
>   It is unlikely to do any damage.  But it will not be reliable.  Chips will
>   often run faster than their rated speed, when the temperature and the power
>   voltage and the surrounding circuitry and the phase of the moon are all
>   just right.  But there is no way to tell whether the chip is just barely
>   working, so that the slightest change in conditions will start producing
>   intermittent random failures.
>
>Actually, if it boots, it'll probably be (reasonably) reliable.  The 80386
>is such a complicated beastie that if it's even slightly flaky, it'll probably
>crash immediately.  It'll probably run hotter 'en 'ell, though.
>
Perhaps yes, perhaps no.  Admittedly, the '386 is far more complex than an
8088; but the following may be applicable anyway.  Experience (my own) has
shown that 5MHz-rated 8088's will run reliably at 8MHz for periods of time
not exceeding 20 minutes before system crashes occur.  The time interval
starts at 20minutes and decreases relatively uniformly until the time interval
is so short that the power-on-self-test won't even start.  This pattern can
be repeated with subsequent parts, indicating it is likely to be always true.
Therefore, based upon the 8088 results, I have to agree with the poster advising
against the use of a too-slow '386 as it will self-destruct after some finite
number of minutes of operation.



Walt K.