FireWire 800 Interfaces

In early 2001 the battle between IEEE 1394 and USB advanced another step with the 1394 Trade Association’s approval of specifications for a faster version of IEEE 1394, called IEEE 1394b. The new standard is backwards compatible – special cables and dual technology cards allowing users transition from the old to new standards without having to retire their legacy FireWire devices – and is expected to deliver data at up to 800Mbit/s, a significant improvement on USB 2.0’s 480Mbit/s.

Moreover, IEEE 1394b’s doubling of the speed of the original version of FireWire over copper wiring is only part of the story. The new standard is expected to eventually allow speeds of up to 3.2Gbit/s and support distances of 100 metres on UTP-5, plastic optical fibre and glass optical fibre, as well as significantly reducing latency times by using arbitration pipelining.

For several years IEEE 1394’s marketing had been somewhat confusing. As well as being referred to by its technical name, the technology was also sold under Apple’s FireWire trademark and Sony’s iLink trademark. In the spring of 2002, the 1394 Trade Association – the group charged with licensing and promoting the standard – sought to bring about a clarification by announcing a deal with Apple that allowed the group to market and license the FireWire name along with the underlying technology. Henceforth the group would encourage companies using the technology to adopt the FireWire moniker, while not forcing them so to do.

So where does that leave the competition between FireWire and USB? So long as the likes of Intel – which integrates support for USB into its chipsets – and Microsoft – which provides support for both USB and FireWire in the latest versions of its Windows XP operating systems – maintain that the two technologies are complementary, the answer is pretty much where they were before the recent speed improvements. With built-in support on nearly every new PC, USB 2.0 will continue to connect devices on the desktop, while FireWire, with its isochronous data transfer capabilities, is likely to continue to dominate the consumer electronics market.

The table below summarises the relative performance of the current FireWire and USB standards, comparing them with the legacy serial and parallel ports they have all but replaced:

Standard Year Introduced Initial Speed
Serial port 1960s 20Kbit/s
Parallel port 1981 1.1Mbit/s
USB 1995 12Mbit/s
FireWire 1995 400Mbit/s
USB 2.0 2000 480Mbit/s
FireWire 800 2001 850Mbit/s