Looking for a way of finding speed bottlenecks across your site? Sitespeed.io runs from the command-line and scores pages against the ySlow scores and captures everything in a clean interface. More information posted here.
Using some of the tools and methods already linked to here at sitespeed.com.au, ReadWriteWeb outlines some great tips.
A fun tool to compare between two sites to see ‘which loads faster’. Options include testing each site on GTMetrix and multiple loads.
Simple test that breaks down the initial HTTP request by time.
For measuring load times segmented by the request handling.
Great comparison tools for PageSpeed and YSlow that combines the site scores in a web-dashboard, allows multiple site tracking and more.
Rules and documentation from Google on Page Speed