pSNOW: a tool to evaluate architectural issues for NOW environments

Performance evaluation plays a crucial role in the design of any system. Evaluation tools should clearly identify, isolate and quantify the bottlenecks in the execution to help restructure the application for better performance, as well as suggest enhancements to the existing design. While there has been significant progress recently in novel network interface designs and system software solutions to lower the communication overheads on emerging high performance Network of Workstations environments, performance evaluation tools for these environments have not kept pace with this progress. In this research, we present an execution-driven simulation tool called pSNOW that provides us a unified framework to model different system software and architectural designs, and evaluate these designs using real applications. Using this tool, we model three network interfaces and three communication software substrates, and evaluate their relative merits and demerits.