I'm thinking of buying an external firewire 800 hard drive to keep my audio recording projects separate from my OS but there's only one firewire port on the iMac and I already have a m-audio firewire 400 audio/midi interface (with a converter). I've read you can connect multiple fw devices by daisy-chaining them. So I assume I'd connect the fw800 hd to the iMac, and then the fw400 audio interface to the hd? Would I see reduced performance on both devices as they're sharing one port? How does the speed/transfer rate of a fw800 hd compare to an internal hd? Do all hard drives allow daisy-chaining?