On my website aprnexgen.com, I have been experiencing a lot of slowness in the past week. It seems that sometimes when I click on something that opens a page, it just says processing then completely hangs, I hit the back arrow and then I can go back to the screen I had problems with and everything is fine. This just happens periodically. Also I was do things on my website for about 25 minutes, I was never idle even 1 minute and I started experiencing the problems I get when I time out. I had to close the browser and log back in.
There are a number of factors that could affect website performance including: 1) Network Connectivity. 2) Website Code that is not optimized. 3) If your site uses a database, you'll want to optimize the queries and index the tables to improve performance. etc. You'll want to test each area to narrow down the problem.
