Why eats my Knoppix so much memory?

[double post]

And did you test how fast php is?

Perhaps you find better hints in a LAMP-Forum.
I guess it's a question of your configuration, or of the implementation of your pages.

But claiming apache to be slow is a very fast judgement.
Keep in mind that most webserver run apache, and ran apache, when 500 Mhz was fast.

I know that :) And I know it must be a configuration problem. But I believe the problem stems not from me as I changed quite nothing in knoppix' / apache configuration.