Why is it that the current heuristic for code efficiency is paying more attention to memory access patterns than to operations counts, when the opposite was true two decades ago?

Why is it that the current heuristic for code efficiency is paying more attention to memory access patterns than to operations counts, when the opposite was true two decades ago?



Because the speed of memory has not kept pace with the speed of processors. Since this trend will continue, the importance of limited and coherent memory access for optimization should only increase.

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