[rescue] What Linux can run on Sun Fire V890 (UltraSparc IV+) server

Robert Darlington rdarlington at gmail.com
Thu Dec 3 10:16:22 CST 2009

On Thu, Dec 3, 2009 at 12:47 AM, Jochen Kunz <jkunz at unixag-kl.fh-kl.de>wrote:

> On Wed, 02 Dec 2009 18:02:17 -0500
> Phil Stracchino <alaric at metrocast.net> wrote:
> > Or, we can all point and laugh when his electrical service panel catches
> > fire from the overload and burns the entire building down....
> Don't make jokes about real world problems of machine collectors! ;-)
> Once I was in the Cray-Cyber basement. I was allowed to power on the
> big CDC-Cyber machine. It runs on 400 Hz three phase power. So it has
> a big motor-generator with flywheel. While spinning up this beast sucks
> 120 A three phase at 400 V. (Thats 83 kW.) Problem: The power feed to
> the basement is rated at 80 A only and there is a big 80 A "NH" fuse in
> the panel. The operator said: Fortunately those 80 A "NH" fuses are
> _very_ slow...
> In minimal configuration the machine needs "only" about 20 kW after the
> initial inrush. The flywheel keeps the motor-generator spinning for
> about one hour after power is removed.
> --

That's only if the computer isn't drawing any current.  The RUPS (rotary
UPS) systems we had at LANL lasted a good 8 seconds when the power blipped
for the ASCI Q supercomputer.

The high frequency power is made by multiple transformer/rectifier stages.
60Hz AC in, 120 Hz out (flip the bottom of the sine wave up to the top),
etc  Do this for all three legs and you get 360Hz output that then gets
filtered with big cap banks and inductors.  This provides very low ripple
going into the rectifiers so you get very clean DC output.  Modern
technology makes this technique nearly obsolete, however it is still used
here and there.  A buddy of mine designed a 720Hz power supply for a big
megawatt RF power supply for driving a LINAC a while back.


> tsch|_,
>       Jochen
> Homepage: http://www.unixag-kl.fh-kl.de/~jkunz/<http://www.unixag-kl.fh-kl.de/%7Ejkunz/>
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