rocknbil - 3:25 pm on Mar 17, 2012 (gmt 0)
Are you using extensionless URL's?
Read the last part of post #4274745 [webmasterworld.com] carefully. The "stock" rewrite reads the entire file system twice and I've seen **major** improvement on wordpress sites using this approach.
Also if you're on shared hosting, most of the time it's a remote mysql server - it could be either of those (shared or the extra connection to the mysql server.)