Thread:Project:Support desk/search box autocomplete slow

I am still new here, and my wiki is starting to have problems with the search box autocomplete slowing down. What took 1-3 sec. now takes 6 sec. to give a suggestion list of pages from the upper right search box. Could I get a top 12 list of common things to do / check when the search box autocomplete slows down? Think it would help me and others. Thank you a head of time.

Product and Version information to take into consideration:

MediaWiki   1.21.2 PHP         5.4.14 (cgi-fcgi) MySQL       5.5.25