If you want more information you might want to look at the High Scalability web site "http://www.highscalability.com http://www.highscalability.com. They discus

If you want more information you might want to look at the High Scalability web site "http://www.highscalability.com http://www.highscalability.com. They discuss a lot of issues related to big, high-performance web sites, and how they scale. Some of the posts are also relevant to smaller sites that want to improve scalability, without investing in expensive hardware upgrades.