I am currently using Magento EE 220.127.116.11 and memcache is also enabled on the server. So the question is whether it's worth keeping Magento compiler enabled? I have read online that the compiler can increase website speed by 25% to 50% but I am not sure whether it's good to do it. Also, PHP APC is disabled on the server.
The Magento Compilation is a feature that allows you to compile all Magento installation files in order to create a single include path. This feature is designed to improve the performance of your online store and is supposed to give between 25% and 50% increase in your page load speed.
Note that before making any changes to your Magento Installation files, the Magento compilation feature should be disabled. To disabe Magento Compilation, go to your Admin Panel -> System -> Tools -> Compilation and click on the Disable button.
if you face problem when compile enable u may take support to magento as Magento EE client
If your issue is for an Enterprise Edition store with a valid Magento Enterprise Edition license, please login to the Magento account linked to the license and open a support ticket for further assistance.
To open a support ticket 1) Login to your Magento Commerce account https://www.magentocommerce.com/ 2) Go to Support > Open a Ticket 3) Click on Open New Ticket 4) Enter the required information and click Submit
The following article will provide you with instruction on adding shared access between accounts: http://www.magentocommerce.com/knowledge-base/entry/sharing-access-to-your-magento-account-for-enterprise-and-community