Parallelism in Cut Off Force Approach

• This is classic “nearest neighbor” problem where one uses “domain decomposition and communicates particles around edge of domain of each processor.

  • Computation a n
  • Communication a n(1-1/d) in d dimensions

Calculation 4 n tcalc

Communication 4 ?n tcomm

Calculation 9 n tcalc

Communication 8 ?n tcomm

2 dimensional examples -- communication and computation both grow as you increase grain size n

Processor Boundary

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