Crash recovery time in InnoDB is fixed - it is dictated by the size of the innodb log files.  It is possible to have faster crash recovery by using a smaller value.

Worth pointing out: the crash recovery code was improved a *lot* in MySQL 5.5 (mysql 5.1 plugin).  It was discovered to be slow with large buffer pool values.  http://bugs.mysql.com/bug.php?id=29847