In this paper we compare the effective bandwidth in a multiprocessor with shared memory using as interconnection networks the crossbar or the multiple-bus. We consider a system with N processors and N memory modules, in which the processor requests to the memory modules are independent and uniformly distributed random variables. We consider two cases: in the first the processor makes another request immediately after a memory service, and in the second there is some internal processing time.
Lang, T., Valero, M., Alegre de Miguel, I. Bandwidth of crossbar and multiple-bus connections for multiprocessors. "IEEE transactions on computers", Desembre 1982, vol. C-31, núm. 12, p. 1227-1234.