When you received a CentOS 6.5 system, you might find out that only PHP 5.3.3 is available. Some research shows, PHP 5.3 is a bit faster than 5.4.x and 5.5.x. However, some CMS or Forum systems will require 5.4 and above version to run them.
Here are the steps to upgrade PHP 5.3 to 5.4.x.
yum install centos-release-SCL
yum install php54 php54-php php54-php-cli php54-php-common php54-php-mysql
php -V// you still see 5.3.x
scl enable php54 "php -v"
php -V// you will see PHP 5.4.x
service httpd restart
Test PHP version, create a simple PHP file to show PHP information:
<?php phpinfo() ?>