Well,

the C fcgi library was faster as expected:

x1. lighttpd/C-fastcgi: 225.41 requests/sec
x2. lighttpd/ruby-fastcgi: 175.22 requests/sec
x3. webrick: 29.02 requests/sec

x1-x2 is excpected, but I think that x2-x3 is too much.
Any comments?

George.