No - you can not disable javascript - EPESI depends on a lot of javascript. I assume you are using Chrome not IE (which is slow and buggy).
Please see this post: viewtopic.php?f=3&t=1616#p5665
where I posted loading time for EPESI loaded with over 1 mln records.
Another article that may help you with troubleshooting: http://www.epesi.org/Troubleshooting
If the demo is working fine for you - and it apparently does work - the problem is with the configuration of your server.
We had different luck with VPS and some hosting providers - reported by few users. Some are very fast but few had problems ranging from slow response to blocking some functionality via custom security settings like PHP mod security which will not let you enter more than one line of text.
The first step is to check your log files - especially php error log - to see if there are any problems with your PHP configuration. Unfortunately without access to your server we can not diagnose the problem. EPESI should open - from the login screen to the Dasboard - in approximately 2-3 seconds, and subsequent modules/screens - in less than 1 second.
