Analysis of multithreaded multiprocessors with distributed shared memory

In this paper we propose an analytical model, based on multi-chain closed queuing networks, to evaluate the performance of multithreaded multiprocessors. The queuing network is solved by using approximate Mean Value Analysis. Unlike earlier work which modeled individual subsystems in isolation, our work models processor, memory and network subsystems in an integrated manner. Such an approach brings out a strong coupling between each pair of subsystems. For example, the processor and memory utilizations respond identically to the variations in the network characteristics. Further, we observe that high performance on an application is achieved when the memory request rate of a processor equals the weighted sum of memory bandwidth and the average round trip distance of the remote memory across the network