Brought to you by Rick James Allocating RAM for MySQL - The Short Answer If using just MyISAM, set key_buffer_size to 20% of available RAM. (Plus innodb_buffer_pool_size=0) (You should be moving away from MyISAM.) If using just InnoDB, set innodb_buffer_pool_size to 70% of available RAM. (Plus key_buffer_size = 10M, small, but not zero.) "Available" memory is what is left over after leaving room f