These are my notes from a talk at Drupalcamp NYC in December 2011 by Sam Kottler, @samkottler on twitter and skottler on drupal.org.
Let's make the LAMP stack go "Vroom!" This is going to be a really high-level overview of performance.
Benchmarking vs Profiling
When we benchmark something, we're setting a baseline to compare against in the future. We want to say "it was this fast this long ago, and here's how we improved." Whereas profiling is telling what is fast and what is slow.
Has a lot of parameters you can set; I'll cover some basic ones.