This week’s Electronic Engineering Times features a short article on the upcoming USB 3.0 spec. The main highlight is a target transfer rate of 4 Gigabits/second (10 times the current rate) providing usable data at 300 Megabytes/second. This rate would challenge IEEE 1394 (AKA FireWire). USB 3.0 is being referred to as “Super Speed USB” and will be “hardware agnostic” according to the article, meaning it could be implemented over copper or optical cabling.
This third variant on the USB theme will adopt a new physical layer, splitting data and acknowledge signals onto separate paths. On the downside, it is likely that USB 3.0 will require a reduction in maximum cable lengths from 5 meters to 2 meters.
The USB crowd is claiming that 3.0 will supplant FireWire, but the FireWire folks themselves are hard at work extending the current 800 Megabit/sec transfer to 3.2 Gigabits/sec. The FireWire spec is due out next year while USB 3.0 silicon is expected in 2009.