Ars Technica has benchmarked tthe top five browsers on Windows

Our readers enjoy our browser market share stories, but sometimes complain in the comments that we don't do enough to compare the actual browsers. We've therefore decided to do some performance tests for the top five browsers (stable and beta versions) on Windows. This is not meant to be an exhaustive performance rundown, as we have not tried every test in existence nor did we run them on every browser for Windows. Also, please keep in mind that we have yet to identify a test that measures all the factors that influence the performance of a browser.

  Windows browsers benchmarked: October 2010 edition