From Mac Guides
FireWire (also known as i.Link or IEEE 1394) is used for connecting high-speed devices and digital video equipment to a computer.
When the FireWire standard was first introduced it was used mainly for connecting camcorders to computers for transferring video. Now FireWire is used in a range of devices that require high transfer speeds, which include; Digital Cameras, iPods, External Hard Drives, etc.
FireWire vs. USB 2.0
The maximum transfer speed of USB 2.0 is 480Mbps while FireWire is 400Mbps. It may seem that USB 2.0 is faster than FireWire but recent Tests have concluded that even though USB 2.0 has a faster maximum transfer speed, FireWire is faster. The reason FireWire is faster than USB 2.0 is mainly because of its architecture. USB 2.0 uses a master-slave architecture where the main controller (The Computer) is responsible for data flow and other functions. FireWire uses a "Peer-To-Peer" type of architecture where each device controls itself, ultimately reducing the load on the main computer which allows FireWire to have a higher sustained transfer speed.
Benefits Of FireWire
- Because FireWire uses a "Peer-To-Peer" architecture the ends of standard FireWire cables are the same because unlike USB there is not a "Master" or a "Slave". This allows the user to connect a range of devices together, for example; Camcorder>External Hard Drive, Camcorder>Computer, Computer>Computer, Camcorder>Camcorder.
- FireWire supports TCP/IP networking, called IP Over FireWire.
- FireWire supports hot swapping, meaning it can be plugged or unplugged while the computer is on.
- Up to 63 devices can be daisy-chained to one FireWire port.
- FireWire 400 (IEEE 1394a) has a maximum speed of 400Mbps (50MBps).
- Two kinds of FireWire 400 plugs exist, 6-pin (carries power) and 4-pin (does not carry power). Most hard drives use 6-pin FireWire, while most digital cameras use the 4-pin variant.
- FireWire 800 (IEEE 1394b) has a maximum speed of 800Mbps (100MBps).
- FireWire 800 uses a 9-pin connector and is not backwards compatible with FireWire 400 due to different connector sizes.
- Most Macs with FireWire can use Target Disk Mode, allowing them to act as an external hard drive to another computer.