Alright, thanks for the howto. Did work like a charm. Afterwards I installed a Test-Joomla and run Code: ab -kc 2 -t 30 http://localhost/joomla/ The result was somewhat sobering and I'm not really sure whether it's a environment issue (virtualbox, 1GB RAM and 2GHZ assigned), but I get very low figures: I learned that the failed requests (Length) are 'normal' due the dynamic generation of content and different size of the results, but just 6.94 requests per second? Without APC it's only 3 something, so APC does have an effect . Is something wrong?