For distributed shared memory multiprocessors, the choice and the design of interconnection networks have a significant impact on their performance. Bidirectional ring networks are considered to be physically fast due to their simple structure, but topologically slow since their communication latency grows at O(N ). In this paper, we will present a quantitative measure to the question of how physically fast a bidirectional ring has to be to overcome its topologically slow communication latency

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... y comparing it to the crossbar, an interconnection network that has opposite characteristics to the ring network. A hybrid method, in which workload parameters extracted from memory traces are given to an analytical model is used for performance evaluation. Our study shows that for a configuration of 32 nodes, the bidirectional ring outperforms the crossbar by 37% on the average of four parallel applications.