Tunning MySQL InnoDB storage engine is not an easy task. It’s more like a game where you set mini goals and then try to find the right value and achieve them. Playing with the InnoDB variables is an art where you have to check your performance results each time you change a configuration parameter. The start point of this game is your MySQL my.cnf file.

Mas:

http://posidev.com/blog/2009/06/30/tunning-mysql-innodb-performance/