I am configuring my Final Cut system and trying to choose what to use as my external scratch disk. Obviously I will be looking for speed, but also portability, and would most likely be using a firewire enclosure for my disk. My problem is, however, that I do not know whether to buy a 1 terabyte 2.5" or 3.5" drive. Do I forgo performance if I use a 2.5" compared to a 3.5", because of their differences technically? A 2.5" drive would be able to be bus powered (and therefore portable) through FW, but if I am using a drive of that size at the expense of performance, then I would much rather be using a 3.5".
Also, while on the subject, I heard somewhere that USB is not particularly good for using as scratch disk access. The person who claimed this was not referring to the slower access speeds compared to firewire, but to something about 'the way USB works.' Would it be possible for anyone to elaborate on this?
Thank you very much for your time.