We don't need nginx to get great performance out of PHP, we need PHP-FPM
For starters check this out... I will be writing up a post in the upcoming hours/day! This should get you started on setting up server/vagrant that doesn't cripple apache. Why, because with PHP-FPM we don't need a separate apache process for every php process. The PHP service now stands alone just like MySQL and can be treated with it's own tuning and process threading. For this example I have used the new apache 2.4 event worker. This is pretty awesome as it is only using php-5.6... I can't imagine how fast this will be when php7-fpm comes out.
Here is a great article: http://dracony.org/stop-using-php-fpm-to-argue-using-nginx-vs-apache/
The main point is that nginx isn't faster than apache simply because it uses php-fpm... apache can also use php-fpm... it's just not as easily configured...(although there may be some quick one liners laying around somewhere).
VAGRANT
git clone https://github.com/bradallenfisher/php-fpm-apache-2.4-centos7.git; cd php-fpm-apache-2.4-centos7; vagrant up
REMOTE VM (LINODE/DIGITAL OCEAN)
yes | yum -y install git && git clone https://github.com/bradallenfisher/php-fpm-apache-2.4-centos7.git && cd php-fpm-apache-2.4-centos7/install && chmod 700 prod.sh && ./prod.sh