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.
Installation of eAccelerator on a cPanel server using phpextensionmgr script
login SSH via root user and run this script.
/scripts/phpextensionmgr install EAccelerator
Once completed just check with php -v command.
/scripts/phpextensionmgr uninstall EAccelerator