Why is MPP always behind the best workstations?
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It takes n extra years to build a new architecture
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Therefore MPP uses sequential technologies which are n years behind
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n=2 implies ~ factor of 3 in cost/performance
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Must reduce delay n by matching parallel design as much as possible to
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Commercial processor chips (use workstation not custom nodes)
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Commercial communication -- (use ATM not custom networks?)
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Commercial Software -- (Use Web not custom MPP software)
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Memory per node (SIMD and MIMD)
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Some say that current machines waste transistors - activity only occurs in 1% of transistors at a time?
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Others say need large memory to run UNIX, increase grain size as problems complicated and further communication needs decrease as grain size increases
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