eAccelerator is a PHP accelerator and optimizer. It helps improve performance by re-using compiled PHP scripts and optimizing them to speed up their execution.
In order to have it installed you will need a dedicated server environment because it requires global server changes. In cPanel its installation is very easy and fast following these two steps:
1. Make sure PHP runs as DSO Apache module. For this purpose log into your cPanel server WHM and go to ‘Configure PHP and SuExec’. There make sure that the PHP 5 Handler is set to dso.
2. Next log in as root by ssh and issue the following command:
/scripts/phpextensionmgr install EAccelerator
With the above simple and easy steps your PHP (site as a whole) performance should be considerably improved with the help of eAccelerator.