>(Of course, the last supercomputer *I* worked on had ECC and, yes, parity
>checked inter-cpu busses...  Of course, I also saw an Ethernet card on one

The Paragon uses ECC throughout I think (interprocessor communication
as well as memory) and I believe the nCUBE uses parity memory.  I'm
not entirely certain of those though.

The problem with parity is that it only catches simple errors.  At
least that's what I see.  I would rather have what I consider slightly
reduced reliability for reduced cost.

And I have heard tell of ``fake parity'' (my term) SIMMs, where the
parity is generated on the SIMM to fool motherboards which require
memory.

And another data point on my list is that I have had memory problems
which were not caught by parity checking.  I had almost six months
where my computer was unreliable, and the problem was a bad SIMM.
Once I replaced that everything worked again.  Parity just didn't
catch that.

--Michael

--
Michael Graff <explorer@flame.org>        NetBSD is the way to go!
PGP key on a key-server near you!         Rayshade the world!