Performance modeling for designing NoC-based multiprocessors

Network-on-Chip (NoC) based multiprocessors have become popular as a scalable alternative to classical bus architectures. The performance evaluation of NoC-based multiprocessors is largely based on simulation. However, precise simulation is extremely slow. Additionally, there are many design parameters that affect the total performance. Therefore, it is practically impossible to use the precise simulation for the design space exploration purposes. To alleviate this problem, prototyping NoC systems and estimating their performances are critically important. In this paper, we present a generalized novel performance model that combined with the simulations for designing NoC-based multiprocessors. We revealed that the performance impact of cache and network latencies are dominant. Moreover, network congestion rarely happens under near appropriate configuration. Thus, the performance model is mainly constructed using the hardware parameters and the statistics that obtained from a simple cache simulation that is separated from the network behavior. The proposed performance model is used not only to obtain fast and accurate performance, but also to guide the NoC-based multiprocessor design space exploration. The accuracy of our approach and its practical use are illustrated through simulation. The results showed that proposed model can estimate performance with only 3.4% error on average and 21% at worst. We also confirmed that our evaluation framework can estimate 360 times faster than the brute force full system simulation.