How do you setup an Alpha cluster

["Gary A. Allen" <gallen ironbark arc nasa gov>]

Folks,

A bunch of us at the STA Branch of the NASA Ames Research Center are sold on
the idea of using an array of Alphas running on PCI bus motherboards to do
scientific computations.  Our ideas are currently embryonic:  We are thinking
of having several desktop Alphas with Linux and Windows-NT partitions
(Windows-NT for shrink-wrap software and Linux for doing real scientific work)
and also having a large cluster of Alphas dedicated to scientific computations
using parallel algorithms. The large cluster would run with Linux as the
operating system and use applications compiled with the best legal compiler
available for Linux.  Our machines would all be based on the new OEM Samsung
chips and motherboards.   All of the generic PC stuff (cases, CRTs, keyboards,
video cards, hard disks, etc.) would be purchased at bottom dollar from local
vendors.  We would assemble the machines in-house and wire them together using
high speed Ethernet connections.

The basic idea is our engineer/scientists would use their desktop machines
for code development or pure scalar computations and farm out their extremely
parallel algorithm CPU intensive work to the Alpha cluster.  The primary
scientific application would be trajectory and computational fluid dynamic
simulations of spacecraft entering planetary atmospheres.

Great minds work alike!  I understand that a bunch of people at Los Alamos and
other places have built up Alpha clusters based on PCI bus motherboards and
the special effects for Titanic came from the same sort of architecture.  I'm
a newbie humbly seeking advise from people who have actual experience building
these systems.  Is this basic concept a dumb idea?   For example: would fast
Intel or AMD chips running Linux be a better approach.  Is using Linux a dumb
idea?  Should I (shudder) be using only Windows-NT?  What are the hidden
pitfalls one encounters with an Alpha cluster that do not appear until after
the system has been built and running for a few weeks?  Is using an Ethernet
message passing approach the best basis for an Alpha cluster running parallel
code?   What's the optimal top CPU speed for an Alpha cluster?  For example
if the Ethernet latency is the primary data bottleneck then a cluster based
upon the more expensive 800 Mhz. CPUs might perform no better than 533 Mhz.
CPUs.  Our goal is to maximize CPU-cycles/dollar.  We understand that there
are faster architectures out there (Cray T3D) but we can not afford them. 

                            Thanks in advance!
			    Gary A. Allen, Jr.