USB 2.0 on the Horizon

Electronic News, Nov 29, 1999 by Scott Hudson

The Universal Serial Bus (USB) is a standardized connection between the PC and many peripherals. The current USB 1.1 technology carries data at two rates: 1.5Mbit/sec. for the lowest speed devices, such as gamepads, joysticks and mice, and 12Mbit/sec. for medium-speed devices, including printers, floppy drives, etc. USB at 12Mbit/sec. is 100 times faster than the serial port and 10 times faster than the parallel port. The USB 2.0 specification draft was released at the USB 2.0 Developer Conference that was held in October. The new top speed for USB 2.0 is 480Mbit/sec. The release of the final specification is targeted for the first quarter of 2000, but many believe that this date will slip.

Once a final specification is established, it will take several quarters for USB 2.0 peripherals to appear on the market. The most optimistic forecast shows these PC peripherals available in the second half of 2000. Now with USB 2.0 running at 480Mbit/sec., the bandwidth requirements of most advanced PC centric peripherals is achievable. Other significant advantages of USB 2.0 are the use of existing cables and connectors and forward/backward compatibility with USB 1.1.

So what are the benefits of USB? USB allows for true plug-and-play compatibility and eliminates the problems of add-in cards and system reconfigurations. Once a USB peripheral is plugged into the PC, it is immediately recognized and the appropriate software is activated. Using standalone or peripheral hubs, up to 127 devices can be daisy-chained. Other USB advantages are high-fidelity audio, two-way data and a built-in power supply.

What does the impact of USB 2.0 mean for IEEE 1394? Without a doubt, 1394 is the performance leader with 100Mbit/sec. to 400Mbit/sec. currently available and future data rates pegged at 800Mbit/sec. to 1,600Mbit/sec. Just last year at the Fall Intel Developers Forum, there was much discussion of 1394 being prominent on the 21st century PC. Since then, Intel Corp. has rethought this strategy and has relegated 1394 to the consumer-centric devices . In fact, Intel has stated on numerous occasions the 1394 will never be incorporated into its chipsets.

Experience with USB 1.1 shows that two things need to be in place for the USB 2.0 market to fully develop. One, Intel must implement the host controller in the core logic chipset and two, Microsoft Corp. needs to provide software drivers as part of the Windows feature set. Intel plans to have a USB 2.0 host controller integrated into the chipset by the end of 2001. Until then, discrete host controllers will be needed. The final success of USB 2.0 depends on cost. If USB is at or below the price of 1394 by the fourth quarter of 2001, then USB 2.0 wins, if not, 1394 could be a dominant technology in PCs.

Scott Hudson is a senior analyst with Cahners In-Stat, covering computers and information appliances. He can be reached at shudson@cahners.com