Dear all,

thank you very much for your answers. What I did some days ago was installing APC (Alternative PHP Cache) on the server. I could not believe the results, but still - days after - they are as good as they were from the start. Server Load dropped like crazy. The momentary average server load is < 0.60, while it was >2.00 before. Therefore the need for any further optimization has vanished. Again, thank you both for taking the time to answer to my question.

Kind regards
-Amitz