Using Lighttpd: apache proxy or direct connection?
Solution 1:
Generally you do this because apache processes take as much memory as the largest script that has run in them. So with lots of connections you have a lot of memory taken up unnecesarily, limiting the number of simultaneous connections that you can deal with. Even if you were to use a seperate apache instance for static files you would see the benefit.
it is not so much about scripts blocking processes but making best use of resources.