[Beowulf] High quality hardware

[Mark Hahn]

> countinuous "lamd" daemoun hangups. But the next day all nodes ran
> almost fine with identical test suites. Moreover, now it's giving very

but do you have monitoring of, for instance, temperature?  lack of
repeatability will make your life very difficult.

> 	-Continuous run 24h a day of common hardware not prepared to.

which generally equates to temperature.

> 	-Defective mainboard/memory 

but what you describe is a degredation, no?  that is, it used to work fine,
but now, sometimes intermittently fails?

> 	-External inteferences/noise

are these systems based on bare boards?  or multiple boards per chassis?

> The last argument seemed to gain our attention, in that case what would
> be the best case material for shielding ?

mu-metal, I suppose.  but that's rather extreme!  are you proposing some 
kind of EMF interference *through* the case?  or some kind of exotic noise

> Also, what kind of mainboard manufacturers do you trust most ? I'm

I go with "A-list" vendors: recognizable vendors, preferably not entirely
focused on either low-end or gamer markets.  asus, tyan, supermicro, msi,
celestica, hp, ibm, apple, dell, etc.

> referring mainly to Socket A platform,

ah.  I wonder if that's your problem, then.  socket A has always had a rep
for being somewhat fiddly to run stably, and to keep cool.  the latter is 
presumably just because the chips dissipate a fair amount of power, and need
rather good contact with a rather good heatsink.  unlike intel or recent AMD
systems, which have builtin heatspreaders.  still, if you have properly
mounted, fan-working, copper heatsinks with good through-case airflow,
I'd think you could expect stable behavior.

> we're currently using Asus and
> MSI but alse Tyan seems a good option.

those work for me.  oddly, I'm getting feedback from OEM channels that Tyan
is having trouble stocking/delivering products.  that's kind of worrisome,
since I tend to like their products...

regards, mark hahn.