TECHNICAL ARTICLE Modeling and Simulation of Multithreaded Architectures

Multithreaded architectures are widely used for, among other things, hiding long memory latency. In such an architecture, a number of threads are allocated to each Processing Element (PE), and whenever a running thread becomes suspended, the PE switches to the next ready thread. We have developed a simulation platform, MTASim, that can be used to test and evaluate various policies and parameters of a multithreaded computer. The most important features of the MTASim are its flexibility and its ease of use. The MTASim model is based on finite state machines and can be easily modified and expanded. The simulation platform includes an experimental planner, an interface to PVM for the execution of independent experiments in parallel, and an interface to Matlab for processing and displaying results. The MTASim has been used to, among other things, determine the optimal number of threads and to evaluate various prefetching strategies and thread replacement algorithms