>>>> "Allison" == Allison
<ajp166 at bellatlantic.net> writes:
Allison> The real problem with water is not it's conductivity. High
Allison> power tube transmitters have used distilled water in the
Allison> past as it's a really poor conductor if kept clean.
Allison> DEC experimented with water cooling too. The Aquarius
Allison> project was a water cooled VAX. Too many headaches with
Allison> leakage, heat transfer to the environment and installation
Allison> issues. Systems like that use a chiller and heat exchanger
Allison> to cool the closed loop water system. Those are costly and
Allison> difficult to install. Murder if it should leak in a
Allison> computer room. Then there is an efficientcy problem as you
Allison> end up using power to move heat which adds heat..
Allison> With all that, the circuits they were trying to cool were
Allison> getting more power efficient. So by time they worked out
Allison> wet cooling air cooling was again attractive or at least far
Allison> easier.
I remember that episode. The result was "Aridus" :-), now known as
the 9000.
Allison> It's still packaging. ;)
Yes. And if your circuit density isn't all that high, air cooling
works fine.
That's why Cray actually had to solve these problems, and did back in
the early 1960s (CDC 6600), because he DID build things that could not
sanely be cooled any other way.
I don't ever remember hearing of leak problems in our Cybers...
paul