Here's a little secret not many Linux administrators know:
If you don't care about post-mortem analysis of a system and just want it to perform much faster, especially if you're running MySQL just remount the partition where your databases are stored with the noatime option:
[root@host]# mount -o remount,noatime /var/lib/mysql
This will improve the system I/O by at least 25%.
The only drawback is that none of the file's atime (access time) will be updated.