Tradeoffs with Inherent Communication

• Partitioning grid solver: blocks versus rows

  • Blocks still have a spatial locality problem on remote data
  • Rowwise can perform better despite worse inherent c-to-c ratio

• Result depends on n and p

Good spacial locality on

nonlocal accesses at

row-oriented boudary

Poor spacial locality on

nonlocal accesses at

column-oriented

boundary

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