My site was never loading that quickly because I hosted it at home.
However since a month I moved my website to a dedicated server with a 100 Mb duplex connection.
I also updated Apache to version 2.4.1 (from apachelounge) and updated php(5.4) and mysql 5.5.22.
I also updated my website to joomla 2.5 and also updated my plugins.
The plug ins I use: The default joomla one’s + Seobooster, SEOSimple,System - SEF(joomla’s default one)
, jFinalizer, JotCache , System - Cache(joomla’s default one)
I use them in the above order and used them when I was hosting my site at home(but older versions).
I’m using windows server 2008 R2 64 bit sp1 and I also run some game servers on this box.
I did a lot of webpagetests and tried to optimize the loading performance of my website but it still isn’t that great.
As you can see the content download times take long, and I don’t know why.
This problems happens when all my other software is turned off and the cpu usage is 0-10% and it also happen when the game servers are active and the cpu usage is 60-90%
Also the time to first byte is sometimes getting bad rattings, in this case it was fine.
Example of an older test with a bad time to first byte: http://www.webpagetest.org/result/120327_YF_3R4TX/
This is a chart of the google webmaster tools site performance lab.
As you can see the performance got worse ever since I got a dedicated server… and because it isn’t a performance issue with the hardware or network I think its a software issue with apache, php or joomla.
I already tried some tweaks like reducing the file sizes by enabling compression and by using smaller resolution images which helped a little bit.