Step 1) Switch from MyISAM to InnoDB (e.g. XtraDB)
Step 2) /etc/mysql/my.cnf
default_storage_engine    = InnoDB innodb_log_file_size = 128M innodb_buffer_pool_size = 8G innodb_file_per_table    = 1 innodb_open_files    = 400 innodb_io_capacity    = 400 innodb_flush_method    = O_DIRECT innodb_flush_log_at_trx_commit    = 2 innodb_thread_concurrency = 8
These settings are optimized for 12GB RAM
Enjoy the speed of your Mysql **PERCONA