USB (Univeral Serial Bus)
USB 1.1:Transfer limit of around 11Mbps (or around 1.5MB per second)
USB 2.0: Transfer rate of 480Mbps or around 60MB per second.
Firewire
FireWire (other terms include iLink, IEEE 1394 or 1394EEE) provided both the transfer speed, at 400Mpbs (50MB per second), and consistent rates (guranteed).
FireWire 400 (IEEE 1394a): 400 Mbit/s data rates (50MB per second)
FireWire 800 (IEEE 1394b): 800 Mbit/s data rates (100MB per second)
Differences in the real world:
At first glance it would appear that USB 2.0 is even faster than FireWire (400); however speed is not the only issue when it comes to DV. One serious issue with USB 2.0 is that it can not guarantee a specified data transfer rate. This is due to USB 2.0 being a master-slave technology, which means it needs a computer's CPU to coordinate the appropriate data transfers. While not a problem when dealing with low demand peripherals such as Web cams, scanners, printers etc, digital video requires dependable performance to avoid dropping video frames.
FireWire is a much more independent technology in that it works in a peer-to-peer relationship. For this reason, many professional DV users are now able to download their video from a DV camcorder to an external hard drive without the use of a PC. Finally, and most importantly, FireWire delivers data consistently at a specific rate. If you want to work with video, even to edit the family movie, go with FireWire.
Exterts taken from
Digital Video Cameras Buying Guide
