[Beowulf] Infiniband Support ?

[Mark Hahn]

> We have a small cluster of 16 nodes (single socket) with Intel S3210SH

this is an LGA775 board (dual core xeon 3[0123]00, 
dual-channel ddr2/800) with two builtin Gb ports.

> motherboards. Does it fully support to connect these nodes with infiniband
> switch and also installing the relevant iniband host adapter/interface
> cards?

infiniband is fairly forgiving, though you are unlikely to be able to drive
recent IB cards at anything close to peak performance.

> Is it worth to add such an high speed interconnect for such a general
> purpose cluster?

it depends what you mean by "general purpose".  if you have applications 
which currently struggle with the Gb interconnect, it's hard to see how 
even SDR-generation IB would not help a lot.  on the other hand, these 
are really quite slow nodes by today's standards, and adding IB is not 
going to make them competitive with even entry-level modern nodes.

> If there is no support possible with infiniband then can we plan for any
> other high speed interconnect technology like Myrinet, Quadrics etc.

really?  I'd be curious to know how much Myrinet and Quadrics is still
operating, world-wide.  I still run a large Quadrics cluster, but it feels
very much like a curation project and a rather desperate one.

offhand, I'd recommend making sure your Gb is operating well, before sinking
money into an older cluster like this.  for instance, perhaps your Gb switch
isn't all that great (higher latency?  not full-bandwidth?).  it would 
probably be worth checking into openmx, for instance.  if you're not
currently using both Gb links, that might be a good idea as well.

regards, mark hahn.