I've now got 3 hard drives and a DVD-RW and I'm not 100% sure if I've got them setup for maximum performance. Currently I have:

Main HDD as primary master
2nd HDD with mp3s, video etc as primary slave
DVD drive as Secondary master
3rd HDD with mp3s etc as secondary slave

Is this totally screwed up? Should I maybe have my main HDD and DVD burner on the same IDE channel?