> note that infiniband isn't a high speed interconnect. it's a cheap commodity interconnect- in fact, per port, it can be cheaper than 10GB. Why do you think t

> note that infiniband isn't a high speed interconnect. it's a cheap commodity interconnect- in fact, per port, it can be cheaper than 10GB. Why do you think that an interconnect can't be both cheap and high-speed? As you said, there has been a lot of work to make MPI efficient on infiniband, but that has been possible because inifiniband offers much lower (~10 times) latency than 10GbE, not because no one has optimized MPI for ethernet. In fact, standards like RoCE and iWarp have been devised by Ethernet working group to compete with infiniband on this particular metric.