[Beowulf] Home Beowulf - NIC latencies

[Mikhail Kuzminsky]

>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.
I'm very glad that parallelised chessprograms are developed,
but I'm regretted that chess programs don't have coarse-grained 
parallelizm ... :-( I thought that every processor can handle
some big part of moves tree. Unfortunatelly I can't win Deep Fritz 8 
also w/o parallelization :-)

>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?
   One idea for "low price & low latency interconnect infrastructure"
may be ATOLL (//www.atoll-net.de), because it has no "external"
switches. But I don't know about commercial availability of ATOLL 
hardware just now.
>Please note MPI is probably what i'll use, though i keep finding online
>information about 'gamma'. Is that faster latency than MPI >implementations?
   You can use MPI over GAMMA having more low latencies.

Yours
Mikhail Kuzminsky
Zelinsky Institute of Organic Chemistry
Moscow

>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