Alternative hardware approach

[Jerzy Kakol]

Ho folks,

Surfing hardware sites recently I descovered very interesting hardware
solution: Single Board Computers. However those I found here and there are
still too expensive for home-built Beowulf cluster, especially comparing
them to common PC mobos. Does anybody know about cheap SBCs or highly
reduced PC motherboards? My question comes from realizing that most of PC's
motherboard equipment is spare (as well as the whole PC itself). Ideal base
for cluster's single node would be, I think, a motherboard with integrated
Ethernet card and WITHOUT floppy controller, ISA slots, PCI slots, (not sure
about EIDE or SCSI controllers, perhaps performance issues disqualify NFS as
a node's filesystem) - just proccessor, memory and Ethernet as i/o device
plus eventually a single hard drive controller and single serial port. Such
thing would allow to build relatively cheap clusters consisting of hundreds
of rack mounted nodes (no PC cases, they are also spare expense). Is there
something like that available on the market fairly below $100?

I wondered also if it would be possible to build a cluster based on SBCs
inserted into so called passive backplanes. Does it mean that it would
involve MPI implemented over PCI instead of Ethernet? Maybe it means also
another level of non-uniformity (in the same sense as in case of NUMA):
first level - SMP, second level - set of SBCs communicating over PCI bus
within a single backplane, third level - set of backplanes connected to an
Ethernet switch through Ethernet NIC occupying one slot on each backplane.
Does it make a sense for you?

  George Kakol
 jkakol@cympak.com
 CYMPAK, INC.
 tel  (215) 826-9440
 fax (215) 826-9558
 3930 Nebraska St.
 Newportville, PA 19056