I will be buying final cut x when it comes out. What should I look for specs for a scratch disk? Can I use a portable 2.5 hdd through firewire? should it be buss powered or external power supply? in the near future i will be buying a new computer with Thunderbolt port should I buy ssd or is it necessary for a scratch disk. Also do I want to store my video and edit it on the same drive? (I am talking external, as I have read that it is not good for performance or drive to edit video on same drive as program is stored) how about once the project is done should it be moved to a different drive for storage?