Learner Profiles

Sam

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Sam wants a number for whether more cores helped. The number is the efficiency, T(1) / (N * T(N)), next to the speedup T(1) / T(N). In the worked series, 8 cores take 1.6 seconds where 1 core takes 8.0. The speedup is 5 and the efficiency is 0.625. The cores helped. Each added core contributed less than the one before it. A shorter real line means less time waiting. The efficiency says how much of the extra machine showed up in that wait.