What is the limit? (was RE: multi-homing fixes)

Fri Aug 31 11:20:31 UTC 2001

> You're not the first to tell that i'm talking nonsense; but i had both
> experience with a water-cooled computer (not something i wish to repeat),
> _and_ designing hardware for COs (heck, the first computer i laid my hands
> on was using thyratrones (sp?) for triggers, and quite a few relays).

Well, I really don't want to play "Can You Top This?"  (The name of a national
radio program when I was a child), but the first computers of my experience
were mechanical analog machines--all gears and cams and such.

I think the word is thyratrons.

> Not everything which works in one-of-a-kind supercomputers is workable in
> your average central office.  People who build equipment which has to work
> for years w/o interruptions, survive quakes, power faliures and
> thick-fingered technicans are not idiots; and if water cooling was a real
> solution for CO environmental control woes, they'd use it.

UNIVAC 1100/90's and IBM 3090 K's (I am not sure of the IBM nomenclature,
I never actually worked on one) were hardly one-of-a-kind--there were three
or four 90's and at least a couple of the IBM machines in Hayward (look up
that place name in a fault catalogue) and Concord.  The Bell System 
probably had 50 or more /90's at the peak (how many 4A crossbar's did they
have?)

> In an average CO a poodle on a floor has a risk of not being noticed for
> a couple of months.  It doesn't have an alarm relay, you see?

That would be pretty silly--I have not worked in a CO environment for
a lot of years, but I can't imagine one without such alarms.

> (Have you ever seen a blast of H2/O2 mix resulting from electrolysis? No?)

All of the water cooled computers of my experience have the water inside
plastic plumbing.  Unless somebody leaves the plug out of the bottom
of a tank.

And by the way, the CO's around here seem to get flooded some--tornadoes
rip the roof off, the Missouri disagrees with the Corps of Engineers, or
a bunch of elm tree leaves plug up a street drain.

The point here is not that liquid cooling electronics is the best, cheapest,
or even very good.  The point is, the technology exists, and ut works.

That it is more expensive than air-cooling is pretty obvious.  But I think
the facts are that the reason large-scale electronics are not liquid-cooled
is that in the late 1980's there were breakthrough changes in electronics
designs that greatly reduce the amount of heat produced per some useful
unit of measure.

If things continue as they are and absent another breakthrough change I think
we will be back to where, in order to do what we want to do, we will again
have to use liquid-cooling.  And it will be an unfortunate expense, but it
will work, and it will allow us to do what we want to do.

My last on the subject.