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Showing posts from August, 2004

Network Protocols and Vectorization

Doing things in parallel is one of the older performance tricks.  Vector SIMD machines -- like the Cray supercomputers -- attack problems that benefit from doing the same thing to lotsof different pieces of data simultaneously.  It's just a performancetrick, but it drove the design and even the physical shape of thosemachines because the problems they're trying to tackle -- airflowsimulation, weather prediction, nuclear explosion simulation, etc. --are both important and difficult to scale up.  (More recently, we'reseeing massively parallel machines built out of individual commodityPCs; conceptually the same, but limited mostly by networklatency/bandwidth.)

So what does this have to do with network protocols?  Just as the problems of doing things like a matrix-vector multiply very, very fast drove the designs of supercomputers, the problems of moving data from one place to another very quickly, on demanddrive the designs of today's network services.  The designs of netw…