Follow simple instructions to rebuild Apache through cPanel for best performance. A quick guide for fast learners.

To rebuild Apache through cPanel follow these instructions:

• Login to WHM as Root and follow the path
  Main >> Software >> EasyApache (Apache Update)
• Select radio button "Previously Saved Config" and click on start customizing based on profile
• Select Apache
• Select PHP 5 (latest version )
• Click on Exhaustive Option list
• Find eAccelerator & mod_fscgi and ensure both of these are checked
• Select any options you require, then click on save and build 
• Wait for the build to complete (it takes about 15 minutes, hit refresh to check it's progress)
• You will be prompted to choose your PHP module, select mod_fcgi

If you are running a MySQL based site, we have seen good speed improvements by enabling mod_fcgi and eAccelerator (note you also have to select mod_fgci as the PHP interpreter - you are asked to select the PHP interpreter after the rebuild is complete).

If you enable eAccelerator, you should also make this modificiation:

https://www.vpsblocks.com.au/support/Knowledgebase/Article/View/72/0/eaccelerator-filling-up-tmp-directory