To benefit from using eAccelerator you need to run PHP with phpXisapi.dll. If you run php with php-cgi.exe, each time you request a php page the full "PHP env." is loaded and unloaded at the end of serving each single php page. So no benefit in using eAccelerator.

You can also run php in a hybrid configuration using a semi-persistent "php env." for php-cgi.exe with techniques like: Setting up PHP as Fast CGI (FCGI) under Apache.