Bestec power supplies, in a notorious run provided to E-Machines and HP, would blow, killing the motherboard - but not the hard drive, processor, or any other peripherals.

The breaker function internally is supposed to try to stop that from happening, but almost all manufacturers of power supplies cut massive corners to save pennies. Antec, for example, does fantastic designs. Then they pull caps out of the units until they stop working, then add one back in. They then use Fuhjyyu and other craptastic capacitors to build the power supplies. Rubycon, Samsung, even United Chemicon are VERY rare to see in consumer power supplies. Instead, it's Teapo (so-so), Capxxon, and the aforementioned Fuhjyyu. These are 'two years, at best' capacitors.

There _are_ some brands that don't suffer from it. PC Power and Cooling tends to overbuild their power supplies - it's what I use in machines I don't want to die.

Now, what's shocking me is that the surge sounds like it was on the 12 volt rail, rather than the 5 volt rail. Usually, unless you see lightning coming out of the supply, the peripherals tend to survive. (not necessarily the raid controller, however)

(Yes, I HAVE seen lightning come out of a power supply. That was fun, until I could get it unplugged. You could watch the light show from outside and have a good idea of what part of the board the arcing was following)