Re: [PLUG] AMD or Intel P4??

[Sean Finney <seanius@seanius.net>]

On Sun, Jun 09, 2002 at 05:34:49PM -0400, Jeff Weisberg wrote:
> 
> | how high end can an intel machine get?  Not very.  I will
> | be impressed when I see an intel machine that can compete with an E10k.
> 
> 
> The 5th fastest supercomputer in the world, "ASCI Red" is a ~9600
> node Pentium Pro (200 MHZ) based system. It runs at 2.4 TFlops.
> It contains 2 storage subsystems, each capable of 1 GByte/sec.

just to chime in my $0.02, I think these are two different ideas of fast
here.  in one case you're talking about what's mostly a transaction-based
server system, and in the other a time-sharing mainframe.  Teraflops
aren't really a gauge of individual application speed as much as they're
a gauge of how much work you can get done in a certain amount of time.

also, the speed they've given is probably a theoretical peak.  an average
parallel application won't run with those kinds of numbers, especially
on a 9600 node system.  For example, I worked on what i think is still
the #3 contender on the site you mentioned.  seaborg's peak speed was
estimated to be about 3 TFlop/s, but to have something actually produce
those kind of numbers you a) have to have sole posession of cpu time on
all nodes and b) have to have written a program that can evenly distribute
a job into the ~200 nodes of the system.  i'd imagine it's a little harder
to do the same for a 9600 node system.  and you still will often have
a huge bottleneck when it comes time for doing any kind of i/o.   

if you were using the DOD ASCI red system to run a webserver,
(ha ha, tax dollars at work), in the end you'd still be connecting to
a single 200 mhz pentium pro node on port 80.  maybe someday when SSI
clusters actually work for production systems, or if apache decides to
have some fun with MPI, that'll be different.  in the meantime, i'd
be willing to wager a sun server would outperform asci red for your
webhosting needs :)

--sean

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