Real-time constraints place additional limitations on distributed memory computing systems. Message passing delay variance and maximum message delay are important aspects of such systems that are often neglected by performance studies. This thesis examines the performance of the spanning bus hypercube, dual bus hypercube, and torus topologies to understand their desirable characteristics for real-time systems. FIFO, TDM, and token passing link access protocols and several queueing priorities are studied to measure their effect on the system’s performance. Finally, the contribution of the message parameters to the overall system delay is discussed. Existing analytic models are extended to study delay variance and maximum delay in addition to mean delay. These models separate the effects of node and link congestion, and thus provide a more accurate method for studying multicomputer networks. The SLAM simulation language substantiates results obtained analytically for the mean and variance of message delay for the FIFO link access protocol, as well as providing a method for measuring the message delay for the other link access protocols and queueing priorities. Both analytic and simulation results for the various topologies, protocols, priorities, and message parameters are presented. / Master of Science