Yes, set the number of fcgi processes started by mod_fcgi to 1. The reason is that apache mod_fcgi spawns already one process per apache child so that php does not have to spawn its own childs. If you would spawn more processes, then they will not get used by apache.
For details on the config options, see here:
http://httpd.apache.org/mod_fcgid/mod/mod_fcgid.html