[Beowulf] Gigabit Ethernet and RDMA

[Gus Correa]

Hello Beowulf fans

Does anyone know the status of  RDMA on Gigabit Ethernet?

Is it a stable solution for a cluster interconnect, or still an 
experimental thing?

Is it effective in offloading network tasks from the CPU?
(Myrinet and Infiniband seem to use RDMA effectively, right?)

What does it take for it to work under typical Linux distributions? 
A driver?
A special kernel?
Something else? 
Just plug the NIC in and play?

Does it support standard MPICH2 and/or OpenMPI compiled out of the box,
or does it require linking to some type of special low level 
communication library,
or perhaps requires the use of a special flavor or MPI (say, from the 
NIC vendor)?

I poked around on the web,
and learned that Ammasso seems to have pioneered RDMA-enabled GigE NICs 
(Ammasso 1100).
Broadcom advertises a NIC with similar characteristics (BCM5706).
However, it is unclear if RDMA GigE NICs would work with standard Linux 
distros,
if it is effective, how much it costs, and how much hassle is required 
to make it work.

Thank you,
Gus Correa

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Gustavo J. Ponce Correa, PhD - Email: gus at ldeo.columbia.edu
Lamont-Doherty Earth Observatory - Columbia University
P.O. Box 1000 [61 Route 9W] - Palisades, NY, 10964-8000 - USA
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