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Theorem 30.4 (First Edition)

What if we do not have enough processors?

Theorem: If a p-processor PRAM algorithm runs in time t, then for any p' < p, there is a p'-processor PRAM algorithm A' for the same problem that runs in time O(pt/p').

Example: p=10, p'=5, A = O(t)
A' = O(10/5 t) = O(t)
Work(A) = Work(A')


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