To some, Thunderbolt is just a port on the side of a MacBook, a mere check-box on a feature list.
But to Intel, the high-speed communication technology is an ambitious attempt to do something that only happens every decade or so in the computing industry: rewrite the rules of how people plug stuff into their computers.
Thunderbolt arrived in 2011 with the potential to bring the flexibility of a tower computer to something as compact as an ultrabook. And it's got a bright future in premium and professional products, as events this week show.
First, Apple's new Retina display-equipped MacBook Pro doubled the number of Thunderbolt ports to two. Second, Thunderbolt arrives in the Windows ultrabook market at the end of the month with the 2.65-pound, $1,400 Acer Aspire S5. Expanding to the Windows world significantly increases Thunderbolt's appeal to peripheral makers, and the S5 is a sleeker product than Acer's 17-inch, Thunderbolt-equipped G75.
Intel's next step could be harder: spreading Thunderbolt broadly to the mainstream.
For all of its promise, Thunderbolt isn't cheap. Right now, the necessary Thunderbolt controller chip from Intel costs more than quadruple that of the equivalent component for an earlier high-speed connection technology, FireWire.
"Thunderbolt is a good spec, but the price is not so good," said Michael Chen, a marketing director for Taiwanese motherboard maker Biostar Group, which sells about 6 million of the electronics boards a year.
Chen estimated that Intel's Thunderbolt chips cost about $35 for a PC and $20 to $25 for devices that attach to it. "This technology -- it may be possible to promote next year with second-generation technology from Intel. It depends on price," he said.
You get what you pay for, Thunderbolt proponents might counter. Its impressive speed suits it well to heavy-duty data demands such as editing professional-grade video that's stored an external drive and shown on a large external monitor. A Thunderbolt port has two communication channels, each able to carry 10 gigabits per second simultaneously in two directions. For comparison, 1080p video at 60 frames per second is only about 4Gbps.
With that flexibility and performance comes high expectations from a company that probably carries more influence over computer hardware than any other.
"Our goal over the longer term, three or five years out, is that it would be broadly deployed across most PCs," said Jason Ziller, Intel's director of Thunderbolt marketing and planning.
By some measures, Thunderbolt is already a success: Apple ships it in MacBooks and iMacs, which sell in steadily increasing numbers. Device makers such as Seagate, Western Digital, and LaCie have released external storage devices that use it. Thunderbolt offers real benefits for professionals and enthusiasts in markets such as videography who can benefit from flexibility and performance. And it's just about to make the leap to Windows PCs.
But input-output (I/O) standards are slow to change, and Thunderbolt has real competition: the ubiquitous USB is arriving in its faster version 3.0 incarnation; HDMI is well established for video; and an upcoming standard called PCI Cable is lurking in the wings as a more direct Thunderbolt alternative.
Success for Thunderbolt will mean it becomes more like Universal Serial Bus, which truly lives up to its "universal" label. Failure will mean Thunderbolt is more like FireWire or eSATA, technologies useful to some customers but not so useful that anyone could count on support being built into computers or peripherals.
IDC forecasts widespread use -- but still a future in which Thunderbolt is more of a luxury option. "We believe in 2016 it'll still be a premium technology," said IDC analyst Linn Huang, reaching about 15.6 percent of laptops that ship that year.
Intel clearly still has plenty of convincing to do.
For an in-depth look at this technology, CNET News has prepared a three-part package: this story on Thunderbolt's fiber-optic origins and the challenge of spreading it broadly; a look at where Thunderbolt is a great idea right now, and an examination of the challenges Thunderbolt faces from USB, HDMI, and the nascent PCI Express Cable. Also, be sure to check out CNET's first look at the Acer Aspire S5.
Lower costs, higher volume
Happily for Intel, there's a way to ensure Thunderbolt becomes a fact of life rather than a footnote: lowering its price.
Going from premium to mainstream adoption is like going from orbit to escape velocity: it takes a lot more energy. For Intel, lowering the price is like adding rocket fuel, and opinions differ on whether Thunderbolt will merely attain a higher orbit or whether it'll break free.
And Intel knows the drill. "We are working on bringing the cost down. With any new high-performance technology it starts higher and you work your way down," Ziller said, including a dramatic cost cut to today's $50 cables. "We don't expect it to be niche."
The cost hits peripheral makers as well as PC makers.
"It's about four to five times more expensive than FireWire, and FireWire is not inexpensive," said Jim Sherhart, senior director of marketing at storage system maker Drobo. It's one of the reasons Drobo hasn't yet released Thunderbolt products even though it really likes the technology will embrace it soon. "The Thunderbolt stuff is really pricey," Sherhart said, so first-generation Thunderbolt device makers have squeezed out costs by forsaking USB and other ports that would make a device more flexible.
Price will push Thunderbolt either toward USB's ubiquity and FireWire's limited success, said Mark Lee, director of product management for Seagate's direct-attached drive business.
"It's somewhere in between. To what degree it aligns closer to USB or FireWire is cost-depending. That's going to drive the adoption," Lee said. Thunderbolt has a big advantage today compared 1999, when Apple introduced FireWire, he added: "Apple wasn't in the position they are now -- driving technology, being the technology leader."
Another Thunderbolt ally, Acer, sees things Intel's way.
"Thunderbolt, due to cost and other considerations, is going to be on higher-priced products," said Eric Ackerson, a product manager in Acer's mobile group, and initially, the Aspire S5's purpose is to "elevate our brand awareness from a $399 price point to a different user segment."
Eventually, though, it'll spread to more ordinary machines, Ackerson predicts: "My view is that within two to four years, you'll start to see it as a standard connectivity option."
Thunderbolt will certainly ship in somewhat higher volumes. "As Intel opened up Thunderbolt for other platforms as well, the market will expand quite dramatically for Thunderbolt," said Joost van Leeuwen, marketing director at electronics company OCZ, which has been showing its Thunderbolt-based Lightfoot SSDs.
How does Thunderbolt work?
Thunderbolt at its most basic level is an interface that can transfer data between a computer and another device at very high speed. It has two communication channels, each able to send data at 10 gigabits per second in two directions simultaneously. Its low-level communication technology can carry data from two communication standards, PCI (Peripheral Component Interconnect) and DisplayPort.
A notable range of devices can plug into it: external storage products, monitors, RAID storage arrays, external video cards, gigabit Ethernet adapters, and docking hubs that endow a computer with more USB, FireWire, Ethernet, and video ports. Matrox, for example, plans to sell a $249 Thunderbolt hub that will bring USB 3 ports to Mac users who only have slower USB 2 today. It's also got an Ethernet port, which MacBook Air owners might appreciate, and an audio input port, which is handy for better sound quality in VOIP and video calls.
That versatility makes Thunderbolt well suited to a new era in which laptops are used for tasks like video editing that were once done on desktop machines. But laptops are difficult or impossible to expand, and in an era of ever-thinner laptops, a single Thunderbolt can shoulder a much heavier load than USB. Thunderbolt and ultrabooks were made for each other -- literally.
"For anybody looking for nice way to do the kind of expansions that you used to do by opening up the box and installing a card, this provides some similar capability," said Insight 64 analyst Nathan Brookwood. "That's one of the reasons Apple was quick to jump on that."
Take for example Elgato's Thunderbolt SSD drives. Thunderbolt makes the performance of SSDs available in an external drive, giving a fast new expansion option to laptop owners. These models aren't cheap, though: $430 for 120GB or $700 for 240GB. And LaCie's Little Big Drive is even more expensive at $900, but it includes a useful second Thunderbolt port.
The multilingual abilities of Thunderbolt are one of its biggest advantages. Thunderbolt's versatility gives it more value -- at least if lots of companies making storage devices, external monitors, and other peripherals jump aboard. FireWire and eSATA, by comparison, have narrower uses.
To reach its high speed, Thunderbolt needs several ingredients. First are proprietary controller chips supplied exclusively by Intel; in a PC, such a chip package is 12x12mm and draws a nontrivial 3.4 watts maximum. Second is the port itself; for that, Intel recycled the Mini DisplayPort hardware first introduced by Apple for attaching external monitors. Third is an active cable, meaning that built-in chips are necessary to relay the signals from one end to the other. At $50 from Apple, the cables today are expensive.
But the cables play an important role, because Thunderbolt devices can be linked from one to another in what's called a daisy chain. For example, you can plug an external hard drive into a PC, then external monitor into that hard drive. Thus, a single Thunderbolt port can be more useful than a single USB port.
Historically, PCs used separate interfaces for video and data connections, but Thunderbolt combines two such interfaces into one: PCI Express, a technology typically found only inside computers and used for plugging in things like network adapters or graphics cards; and DisplayPort, used to run external monitors. The approach means that one pesky part of support is already done, the software drivers that operating systems need to communicate with devices. Thunderbolt itself handles the task of juggling the different types of data being sent.
Thunderbolt began its life as a project called Light Peak that sought to endow USB with a higher-speed fiber-optic link.
Instead, what emerged in the marketplace was transformed significantly: Thunderbolt employs the Mini DisplayPort connector instead of piggybacking on USB, and it relies on mundane copper cables rather than the more exotic fiber-optic lines.
The idea of high-speed fiber-optic connections for consumer devices has a certain amount of glamor, but copper has plenty of advantages. It's cheap, flexible, well understood, easy to connect, and capable of carrying electrical power as well as data.
"We'll stay electrical until we need to get to optical," Ziller said.
The Light Peak transition left Sony in the lurch. It was one of the original companies to endorse Light Peak in 2008. But when Sony announced its Vaio Z in 2011, it came with a USB incarnation. Sony sometimes gets criticized for introducing proprietary technology, but this time, the accusation isn't justified: Intel said in 2007 that it hoped to offer fiber-optic links in USB 3.0, but evidently Thunderbolt diverged from this original vision somewhere along the way.
The technology now is heading to the marketplace via the Mini DisplayPort connector and the Thunderbolt brand name. With that approach, Sony spokeswoman Melissa Dolan now says, "We currently have no plans."
Even though copper won in the first version of Thunderbolt, today's Thunderbolt ports support optical connections by virtue of its cable designs, and Ziller promises optical links soon. "I'd say the second half of the year," he said.
In that design, the electrical connections of the port transfer signals onto the cable, but then an optical transceiver in the cable turns those signals into light. The approach means much longer cables are possible -- convenient perhaps for remote storage or for studios with videocameras that are farther away from recording and monitoring equipment.
Copper might be more mundane, but one person who was delighted to see Thunderbolt debut with it instead of the original fiber-optic approach was LaCie product manager Erwan Girard.
"One of my concerns was coming from Fibre Channel storage," which uses optical connectors, Girard said. "Don't bend it, don't touch it, don't put dust into the connector. If you do, you'll have some errors in the transmissions and the performance will drop. Optical was made for server rooms."
Thunderbolt's approach uses metal connections, hiding the fiber optics away solely within the cable, so such interconnection issues aren't a factor.