[Beowulf] Home beowulf - NIC latencies

[Vincent Diepeveen]

Good morning!

With the intention to run my chessprogram on a beowulf to be constructed
here (starting with 2 dual-k7 machines here) i better get some good advice
on which network to buy. Only interesting thing is how fast each node can
read out 64 bytes randomly from RAM of some remote cpu. All nodes do that
simultaneously.

The faster this can be done the better the algorithmic speedup for parallel
search in a chess program (property of YBW, see publications in journal of
icga: www.icga.org). This speedup is exponential (or better you get
punished exponential compared to single cpu performance).

Which network cards considering my small budget are having lowest latencies
can be used?

quadrics/dolphin seems bit out of pricerange. Myrinet is like 684 euro per
card when i altavista'ed online and i wonder how to get more than 2 nodes
to work without switch. Perhaps there is low cost switches with reasonable
low latency?

Please note MPI is probably what i'll use, though i keep finding online
information about 'gamma'. Is that faster latency than MPI implementations?

Note normal 1Gbit cards for normal network traffic.

Each node is a SMP or NUMA node and not only multiprocessor also
multithreaded.

I welcome any advice,
Best regards,
Vincent

Vincent Diepeveen