Selecting the host computer - some notes on qualifying/testing hardware.

I have two used computers headed this way:

• HP Elite 8300 Workstation i5-3570
• Asrock E350m1 (had good latency numbers - It also has a coreboot bios).

I really wanted to get a fanless new machine that ran off of 12Vdc - but I'm afraid of the management engine problems. If anyone has any ideas - I would love to hear them.

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That being said - I used to refurbish computers (by the 100s) that had fleeting and intermittent failures - thought I should share a couple of notes here. (Often people think it is the software - hardware has to work as well) - I hope this is of interest.

One of the problems that took a lot of time to figure out was that both the processor and memory controller have separate throttling features that would produce troubling errors - nothing in logs etc. The cure often was to add a fan to the memory controller. The motherboards manufactures/intergrators - had absolutely zero interest in these problems - continued to ship without proper heatsinks. The details are buried in the chip datasheets that no one reads.

Speaking of heatsinks - most computers come with a heat-sink tab (chewing-gum) that they use because it isn't messy like the compounds. These tabs tend fail after a few years - they get hard - (lots of junk computers just need this removed and replaced. ) Often there isn't an out-and-out failure - Just random glitches that can't be recreated. ( I once wrote this up here )

Which reminds me of other things we did to qualify computers - we heated the memory cards and ran them in an expensive tester - This found only a few problems and today the new memory takes VERY expensive test equipment.

Another way is running special test software with the computer running hotter than it will in service.

Linux comes with burnin - and memtest - but I found that Breakin found things other software didn't. Looks like you can still download breakin free.

Testing computer power-supplies drove me nuts - a lot of the supplies are not so good - the capacitors were rated for a MTBF of only 2 years. I no longer had the rig I built to test powersupplies - pulsing loads to view on a scope is what it took. I would just overrate the powersupply and don't get the very cheap ones..

Hope this helps - <smile>