I have tested my site in pingdom and everytime I get a high waiting time (like 3secs to 15secs) waiting time only for the 1st request. Check here: http://tools.pingdom.com/fpt/#!/bbrzuX/9tutorials.org I'm doing a research on this for a week now, but still dont understand why this is happening only for the 1st request? I have talked with my host, they said that the server is compleately ok and I personally also checked that the server load never gos up more than 3.5, still the same. Any help guys? P.S: My site is fully optimisez and rinning w3 Tatal Cache. Infact I dont use the minify settings as they might increase the load time, maximum css and js are minified.
Most time is spend on "waiting". So... I would seek for javascript functions that wait for page to load (on document ready) to execute or for functions that delay themselves (interval) on purpose.
Running a YSlow test on your site, I found that there are too many HTTP Requests. You load 44 different javascript files and 26 different stylesheets files. You also have 13 javascripts in the header of the page. Putting them at the footer should load the site faster.
To get more information yourself, I recommend to add the YSLOW addon at firefox. You can get it here: https://addons.mozilla.org/en-US/firefox/addon/yslow/