But the specs for the WD HDD say that USB is 480Mbps where as Firewire is 400Mbps.
So how come FireWire is faster??
USB transfers data at 480MBit/sec for a very, very, very short time. Then it takes a break and thinks what to do next. And then it runs again at 480MBit/sec for a very, very, very short time. And stops and thinks again. And so on. Firewire runs only at 400MBit/sec, but it is much better at keeping up that speed forever.