Unformatted text preview: nection network not specified
o༆ λ is not specified beyond λ>>1 -- cannot be
because every machine is different
o༆ Controller, combining network “optional”
Source: Larry Snyder, CSEP524, UW Discuss logP paper here Closing note on logP • Reﬁnements have been proposed over Ime – “Oh, if we also measured xyz, the model would be bemer!” – e.g., logGP: takes “long messages” into account – Challenge: when to stop? CSEP 524: Parallel ComputaIon Winter 2013: Chamberlain 63 Abstract Machine Model Summary: My Take PRAM: Too abstract/unrealisIc! logP: Too parameterized (?) – or, perhaps most appropriate for low- level library writer CTA: The goldilocks soluIon? By analogy: Consider sequenIal programming in a cache- aware manner without worrying about an architecture’s precise… …latencies to access diﬀerent levels of cache/memory …cache lines sizes …etc. It can yield a signiﬁcant fracIon of peak performance, while remaining quite portable CSEP 524: Parallel ComputaIon...
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- Winter '09