Performance analysis and its impact on design

Methods for designing new computer systems have changed rapidly. Consider general purpose microprocessors: gone are the days when one or two expert architects would use hunches, experience, and rules of thumb to determine a processor's features. Marketplace competition has long since forced companies to replace this ad hoc process with a targeted and highly systematic process that focuses new designs on specific workloads. Although the process differs from company to company, there are common elements. The main advantage of a systematic process is that it produces a finely tuned design targeted at a particular market. At its core are models of the processor's performance and its workloads. Developing and verifying these models is the domain now called performance analysis. We cover some of the advances in dealing with modern problems in performance analysis. Our focus is on architectural performance, typically measured in cycles per instruction.