>Is that really the usual case? For me it's about 90% PHP requests, and the
>remaining CSS/JS/Image requests wont be sped up a bit by being served
>through a smaller apache process, because they are already fast anyway.
I think it's a very common case, yes. Let me ask you a question - what is
your MaxClients set to? If it's over a hundred (or even over 50), chances
are you're not using your server's memory as efficiently as you could with
FastCGI/fpm.
>Going FPM would thus mean about double the numberr of processes, and double
>the number of context switches.
Not really, as Apache could be down to a single process and consume a lot
less memory. Regarding context switches - I agree with Dmitry's principle
that it's real life tests that are the only thing that matters, and real
world tests prove that FastCGI is as fast and typically marginally faster
than mod_php (before we take into account the memory savings benefits)
Zeev