locality
1. In sequential architectures programs tend to access data
that has been accessed recently (temporal locality) or that is
at an address near recently referenced data (spatial
locality). This is the basis for the speed-up obtained with a
{cache} memory.
2. In a multi-processor architecture with distributed memory
it takes longer to access the memory attached to a different
processor. This overhead increases with the number of
communicating processors. Thus to efficiently employ many
processors on a problem we must increase the proportion of
references which are to local memory.
(1995-02-28)