Hi, My iMAC has two firewire 400 ports. I going to buy an external drive for storing and accessing my iTunes and iPhoto libraries and camcorder footage for editing with iMovie - I want this connected to the MAC all the time so I'm going have this connected to one of the firewire ports - leaving the other free for my camcorder. but I am going to have to buy another external hard drive soon that I also want to be connected to the MAC at all times. if I connect two external hard drives to the same firewire port via a firewire hub will this slow the performance of the two hard drives (or indeed the computer itself) ?? regards.