Why not USB?
Thunderbolt is leaving some people feeling burned. Rather than drive a new interface into the market, they say, the chip giant should give its full attention to an existing, successful one: USB.
Thunderbolt’s critics say the interface brings new costs and complexity to deliver two bidirectional 10-Gbit/second copper links that won’t open up any major new applications. USB 3.0 is already available at data rates up to 5 Gbits/s over copper and, like Thunderbolt, can also ride optical links in the future.
Simply put, Thunderbolt “is a mistake,” said one big Intel customer.
Their arguments—not generally being aired in the public—are why some of the biggest PC, display and hard drive vendors have yet to throw their support behind Thunderbolt.
The technology will clearly carry a price premium, although Intel won’t say how much. The cost of the controller, currently made only by Intel, will be roughly in line with that of today’s 10-Gbit/s Ethernet chips. That represents a premium over the cost of a USB 3.0 chip.
Further, Thunderbolt requires a unique, five-wire active cable, thus far supplied only by Apple, and modified mini DisplayPort connectors from an unidentified source. Other costs are hidden in the complexities of mastering a new technology, potentially with new supply chain partners.
|Thunderbolt detractors warn of the difficulty of making room for one more connector on space-constrained systems
Apple is the only system maker to have adopted Thunderbolt thus far. Apple, of course, has a business model based on selling generally upscale products, typically with higher-than-average PC profit margins. Most PC and display makers compete primarily on cost in higher-volume markets with thinner profits.
Companies not yet publicly backing Thunderbolt say there are no compelling applications that need more than the
5-Gbit/s links USB 3.0 can offer. Intel managers say Thunderbolt is unique in supporting display resolutions greater than high definition, but that’s a very limited niche.
Thunderbolt will let OEMs have one port that can support either a display or a high-speed data link, potentially simplifying designs, said Intel. But opponents said systems will still need to support existing interfaces, such as USB, and making room for one more connector on space-constrained systems such as ultrathin laptops will be difficult.
Intel argues Thunderbolt will let OEMs build systems that put previously internal resources, such as fast disk drives or graphics, outside the box. Opponents counter that such designs are already possible with a cabled PCI Express spec—and that no one, thus far, has found those compelling.
In the end, Thunderbolt’s detractors want the industry to put the full weight of its collective effort behind USB—a relatively low-cost, well-understood technology that’s already shipping billions of ports across computers, peripherals and consumer devices.
The USB 3.0 version, much like Thunderbolt, was architected in a way that supports its extension to optical links and higher speeds. Intel has not backed USB strongly enough and has delayed plans to support the interface in its PC chip sets, Thunderbolt’s critics say.
Thunderbolt will no doubt get more backing from top-tier PC, display and disk drive makers. But it remains to be seen whether it will provide sustained impact or, like FireWire, flame out.