interconnect latency, disected.

Mark Hahn hahn at
Sun Jun 29 12:37:45 EDT 2003

does anyone have references handy for recent work on interconnect latency?

specifically, I'm noticing two things:

	- many of the papers I see that contrast IB with GBE seem to 
	claim that GBE latency is much larger than I measure (20-30 us).

	- I haven't found any recent studies on where even 25 us of 
	GBE latency comes from.  I recall a really great study from years
	ago that broke a single tx/rx down into an explicit timeline,
	but that was for ~100 MIP CPUs and 100bT, I think.

	- are there current/active efforts to use something other than
	TCP for implementing the usual MPI primitives?  I'd love to see 
	something that used ethernet's broad/multicast support, for instance.

thanks, mark.

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