At 10:52 AM 5/23/2007, Peter St. John wrote:
But oh and Jim if you recall any papers about this I could read that
would be "Jim" Dandy.
I was working off memory, and the iPSC/1 and iPSC/2 manuals I have in
my office as a historical artifact.
I seem to recall that if you google hypercube and intel, you'll turn
up some of the papers that were written early on. The guys who
started with the hypercube interconnect were at CalTech, as I recall,
and spun off to form a supercomputer company embodying that, which
Intel also adopted.
Peter
On 5/23/07, Jim Lux
<<mailto:[EMAIL PROTECTED]>[EMAIL PROTECTED]> wrote:
At 09:19 AM 5/22/2007, Peter St. John wrote:
A hypercube ( http://en.wikipedia.org/wiki/Hypercube) also gets you
exponential space; the max hops is the dimension (3 for a
3-dimensional cube) and the number of nodes is exp(base 2) of the
dimension (8 vertices on a cube). To do a tesseract (4-cube), which
looks like two cubes nested, you'd need 4 ports per node, 16 nodes,
32 cables, max hop 4. I've poked around and don't see a great 4
ports per node solution; I like the suggestion of putting a router
on a motherboard.
Mind you, this is what Intel started with on their iPSC/1 and iPSC/2
computers. The early ones had multiple NICs in the nodes, then,
later, they had a 8 port (I think) router in each node.
It's not clear that this saves anything over a simpler architecture
(e.g. external switch with lots of ports in a crossbar) unless you
can do circuit switched routing (so you don't have a one packet
delay in the switch) AND your algorithm can take advantage of it. I
spent quite some time in the late 80s trying to figure out clever
ways to take advantage of a hypercube topology for a modeling
application.. I'm sure there are algorithms which are a natural
fit, but the ones I was using weren't.
James Lux, P.E.
Spacecraft Radio Frequency Subsystems Group
Flight Communications Systems Section
Jet Propulsion Laboratory, Mail Stop 161-213
4800 Oak Grove Drive
Pasadena CA 91109
tel: (818)354-2075
fax: (818)393-6875
James Lux, P.E.
Spacecraft Radio Frequency Subsystems Group
Flight Communications Systems Section
Jet Propulsion Laboratory, Mail Stop 161-213
4800 Oak Grove Drive
Pasadena CA 91109
tel: (818)354-2075
fax: (818)393-6875
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