Method	Runs as User?	Allows per-site php configuration?1	Requires wrapper script?2	Notes
mod_php	No	apache	No
mod_cgi + php-cgi	No	php.ini	No
mod_fcgi + php-fcgi	No	php-fcgi.ini	No
mpm-itk + mod_php	Yes	apache	No
mpm-peruser + mod_php	Yes	apache	No	Requires modification of main apache configuration file to add a new site3
mod_cgi + suexec + wrapper + php-cgi	Yes	php.ini	Yes
mod_fcgi + suexec + wrapper + php-fcgi	Yes	php-fcgi.ini	Yes
mod_suphp + suphp + php-cgi	Yes	php.ini	No

¹
Allows the use of php_value etc to configure parameters per-site.
In this column, the values have the following meaning:

• apache: either the vhost config file, or a .htaccess file (If allowed in the vhost config. Allowing .htaccess means one extra stat per nested subdirectory per request, and using it means an additional read per request).
• php.ini: php.ini, in the directory (check if this is accurate) of the site. This means one extra stat/read per .php access.
• php-fcgi.ini: php.ini, in the directory (check if this is accurate) of the site. This means one extra stat/read when the php-fcgi daemon is started.

²
Suexec requires a wrapper script either per-user, or inside each sites' DocumentRoot. Yes is considered a bad thing here, since you can't just add your sites' configuration and be done with it. You have to create (copy) a wrapper script, with the possible chance of accidental deletion.

³
This assumes you have your apache properly set up, ie with one (or more) main configuration file(s) containing the main apache configuration, and each vhost in a seperate configuration file (or more then one vhost per configuration file). This (modification of main apache configuration file(s)) is considered a bad thing, since you can't just add your sites' configuration and be done with it.



Further performance tuning