Wednesday, September 19, 2007

USB 3.0 Spec Proposed

There was an Intel press release yesterday announcing a group of companies including Intel, HP, Microsoft, NEC, NXP Semiconductor (formerly Philips Semiconductor) and TI have formed the 'USB Promoter Group' to create a superspeed personal USB interconnect that can deliver over 10 times the speed of today's connection. "We don't want to be the bottleneck in the system," said Jeff Ravencraft, an Intel executive overseeing the USB 3.0 initiative.

More from the press release: "USB (Universal Serial Bus) 3.0 will create a backward-compatible standard with the same ease-of-use and plug and play capabilities of previous USB technologies. Targeting over 10x performance increase, the technology will draw from the same architecture of wired USB. In addition, the USB 3.0 specification will be optimized for low power and improved protocol efficiency. USB 3.0 ports and cabling will be designed to enable backward compatibility as well as future-proofing for optical capabilities."

Some people are saying USB 3.0 will finally supplant FireWire. If it really delivers the 300 Mbytes/second or 4 Gbits/second theoretical speeds it obviously leapfrogs the 400 Mbit/second performance of FireWire 1394a and the 800 Mbit/sec for 1394b and 1394c. If the "Quality of Service" support for HD video also results in a very low jitter interface for audio, USB 3.0 is definitely the way to go. The only advantage for FireWire is cable distance. FireWire's 1394c can work over ethernet cable with speeds of 800 Mbit/second up to 100 meters and USB 3.0 may be limited to only 2 meters. However, it might be a long time before we see any audio interfaces that support 1394c. I've also read that the 1394 Trade Association is reading proposals for a 10 Gbit/second FireWire spec. For more detailed information on this, read this article in EETimes.

It will be awhile before we see any USB 3.0 chipsets and drivers for USB Audio, so this probably won't have any impact on our current development efforts. It would be nice if we finally had an interconnect that was very high performance (meaning it could handle up to 24 or more channels of 24bit/192kHz audio with extremely low jitter) and was available on all shipping PCs.


  1. Hi, interresting post, i m actually wondering which connectics i should choose on a new audio interface, do you know any audio interface already supporting usb 3? i cant find any on the net .. let me know,

  2. I don't think there are any USB 3.0 audio interfaces. After talking to a few companies that specialize in developing both FireWire and USB audio interfaces for many of the existing products, they don't see much of an advantage with USB 3.0 over USB 2.0 except speed. For USB 2.0, you can support up to 64 audio channels. USB 3.0 can handle up to 640 audio channels. I can't think of too many audio applications where you'd need over 64 channels.