A New York Times article has a detailed analysis of Google's infrastructure and discussion with Urs Hölzle, senior vice president for operations at Google. Here are some of the key points I pulled from that article.
+ Google tends builds from ground up versus buying.
+ Google's computing costs are half those of other large Internet companies and a tenth those of traditional corporate technology users.
+ Critics call Google's philosophy "unnecessary and inefficient."
+ "Google is reducing cost while maintaining performance by shifting the burden of reliability from hardware to software individual hardware components can fail, but software automatically shifts the local task and the data to other machines."
+ Google is among Advanced Micro's five largest clients.