I've got G5 dual 1.8 tower. On the back is an 800 firewire port. I'm wondering if I'm getting maximum bandwidth from this port since i've got both USB2 and firewire port used as well. Are these other devices slowing down my 800 firewire drive that's plugged into the 800 firewire port?

In other words, do I need a dedicated independent 800 firewire PCI card for this external hard drive ?