So, I updated EasyPHP from 12.1 to Devserver 13.1 on my local development environment.
I immediately noticed very long loading times on most requests in a Joomla project (from 7 to 17 seconds).
That was weird, as the machine has lots of reserves. While trying to fix this issue, I tried some solutions found on the net, without success.
Here's the solution that worked for me.
Put (or modify accordingly) the following directives in your httpd.conf
EnableMMAP off EnableSendfile off AcceptFilter http none AcceptFilter https none
The AcceptFilter directive actually does most of the job, but setting the other directives, doesn't hurt.