performance in catalyst will depend on things people havent tested yet.

it will depend on whether quicktime can spread the codec image decoding effectively across multiple cpus, and whether they have got disc access to be multi-threaded.

up to now disc access across the entire system has been single threaded - which means only one discs is ever accessed at a time.
so having 2 or more discs doesnt make things any quicker - it still seemed to have to wait for the slowest one...

Catalyst can take advantage of multi-cpus, it is multi-threaded.
but everything important depends on what apple has done.