This blog aims to make a performance comparison between the different MySQL versions/editions and also comparing the differents MySQL forks such as Percona Server and MariaDB. Indeed number of improvements as been done to innodb storage engine in the last MySQL versions. You can find below some of the performance improvements applied to InnoDB these last years (non exhaustive list):
1. New compact storage format which can save up to 20% of the
disk space required in previous MySQL/InnoDB versions.
2. Faster recovery from a failed or aborted ALTER TABLE.
3. Faster implementation of TRUNCATE TABLE.
1. MySQL Enterprise Thread Pool, As of MySQL 5.5.16, MySQL
Enterprise Edition distributions include a thread pool plugin
that provides an alternative thread-handling model designed to
reduce overhead and improve performance.