Sequential Web Frontends/Browsers are the Killer
Response times of any web application are very critical for the end-user experience. Steve Souders takes a detailed look at several large Web sites and concludes that 80-90% of the end-user response time is spent on the frontend, i.e., program code that is running inside your Web browser.
Traditional parallelization techniques and caching are without a doubt very effective in the design of scalable Web servers, databases, operating systems and other mission-critical software and hardware components. Assume that all these components are perfectly parallel and optimized, Amdhal's law still suggests that response time improvements will be very modest, or barely measurable.
