Also working for me is adding these lines to /etc/apache2/mods-enabled/fcgid.conf:
This results in less php-cgi processes. It's good to keep in mind though that the FcgidMinProcessesPerClass seems to override the FcgidMaxProcesses (afaik). In my case having 5 websites configured with suexec (and require a different user php-cgi start) still results in 5 processes. Good thing about this, is that requests do not have to wait for other processes to be quit. But if you run many websites this still may still result in many php-cgi processes.
And in apache2.conf:
in the <IfModule mpm_worker_module> section.
More info about configuring for low memory over here: