On my vBulletin forum, I can search for the posts made by a user by running the following URL: search.php?do=finduser&u=xxx. This returns 250 search results in less than 0.5 seconds.
On the same database but now on XenForo, I can perform the same search with the following URL: search/member?user_id=xxx&content=post
This returns 200 search results in 4.5 seconds:
# Time: 140905 3:08:46 # User@Host: mydb[mydb] @ localhost  # Query_time: 4.505875 Lock_time: 0.000029 Rows_sent: 200 Rows_examined: 511 SET timestamp=1409904526; SELECT search_index.content_type, search_index.content_id FROM xf_search_index AS search_index WHERE MATCH(search_index.title, search_index.metadata) AGAINST ('+(_md_user_xxx) +_md_content_post' IN BOOLEAN MODE) ORDER BY search_index.item_date desc LIMIT 200;
Why the standard search system built in XenForo is slower? Do this have anything to do with MyISAM vs InnoDB? I know the solution is to use the official Enhanced Search add-on but I'm interested to know why this noticeable performance difference.