You will need 8gb to 16gb hdd or flash drive for the OS, it's your decision to pick where you want to boot from, also every other tools are available in the OS, overclocking, flash bios and others
I'd probably put it onto my spare 250 GB SSD, but I would really prefer to run it off of a USB and keep my drive somewhere else. Do you need a USB 3.0 drive so that it's fast enough? So you would use the OS to do the tuning instead of the AMD drivers? Does it automatically override them or something? Thanks for the replies.