The folks at Google are the only people I’ve met who have a clearly stated web performance goal: all pages on their sites will load in 100 ms or less. How fast do you want your site to load? And how committed are you to getting there?
No two performance tests give the same results. To illustrate, I put a high-traffic site, Target.com, through its paces on a handful of commonly used tests — Gomez, Keynote, HTTPWatch and Webpagetest — to see how it performs.