About Mac OS X 10.5 Server, Apache 2 and Performance

Apple published a TechNote related to performances levels of web servers running Leopard Server.
It is recommended to inactivate the cache memory module to improve performance of heavily loaded Apache servers.

Open Server Admin.
Go to Web.
Click Settings.
Click the Modules tab.
Deselect (uncheck) "mem_cache_module".
Click Save.