How and where do you Measure WordPress Performance?

[alex]

Since WordPress is quite common and is the engine for many websites, it's imperative that it performs at it's peak. Many of our existing clients and non-clients have asked us how to gauge their install. Below is a list of the most common, some we have used, others we have not.

Google PageSpeed -> is an excellent way to measure your WordPress site's performance and receive clear, specific feedback on how to make improvements.

New Relic -> also provides a free library for measuring server performance in PHP and MySQL.

MySQL Tuner -> also quickly assesses and makes recommendations for optimizing your SQL configuration settings.

Linux Top -> provides a dashboard for your server's real time performance.
If using Varnish Cache, VarnishStat helps assess the performance aspects of your caching tools.

Zend Server Z-Ray -> provides X-Ray vision and deep insight into your WordPress PHP application 

Additional for Performance Testing

Google Developers: PageSpeed Insights
Mozilla Firefox + Firebug + Hammerhead
Yahoo! YSlow
Google Chrome + Google Speed Tracer
Pingdom
WebPagetest
Gomez Instant Test Pro
Resource Expert Droid