How MacBook Air showcases the battle between USB-C and Thunderbolt

Times are tough for Intel's high-speed port, as even loyal ally Apple offers only USB-C on its new iPad Pro.

Stephen Shankland Former Principal Writer
Stephen Shankland worked at CNET from 1998 to 2024 and wrote about processors, digital photography, AI, quantum computing, computer science, materials science, supercomputers, drones, browsers, 3D printing, USB, and new computing technology in general. He has a soft spot in his heart for standards groups and I/O interfaces. His first big scoop was about radioactive cat poop.
Expertise Processors, semiconductors, web browsers, quantum computing, supercomputers, AI, 3D printing, drones, computer science, physics, programming, materials science, USB, UWB, Android, digital photography, science. Credentials
  • Shankland covered the tech industry for more than 25 years and was a science writer for five years before that. He has deep expertise in microprocessors, digital photography, computer hardware and software, internet standards, web technology, and more.
Stephen Shankland
5 min read
Apple's 2018 iPad Pro, shown here with the optional and Smart Folio Keyboard, gets a USB-C port.

Apple's 2018 iPad Pro, shown here with the optional Smart Folio Keyboard, gets a USB-C port.

Stephen Shankland/CNET

There's a big rivalry inside the slim chassis of Apple's newest MacBook Air.

The laptop's two ports serve double duty, working as both industry-standard USB-C inputs and Intel's proprietary Thunderbolt alternative to connect devices like monitors, cameras and external hard drives. ( Apple calls them Thunderbolt ports, adding to the confusion.) Intel is heavily pushing the higher-speed Thunderbolt, but it's not easy given that USB-C is nearly as fast and enjoys broader industry support.

Apple's other new device shows the magnitude of Intel's challenge. The iPad Pro, arguably Apple's embodiment of the future of personal computing -- has a USB-C port without the Thunderbolt abilities. Apple's decision might well encourage mobile device companies to get more serious about USB-C, but it sends the opposite message about Thunderbolt.

"It's really hard to know why two standards are needed," said Endpoint Technologies analyst Roger Kay.

Apple's inconsistent embrace of Thunderbolt underscores its rocky road as a mainstream port. It's based on a technology born of traditional personal computers, and shows few signs of expanding beyond them. Even in higher-end PCs, there are risks to relying on it. What video editor wants to be left in the lurch when trying to share a big file with a client who can't plug in the Thunderbolt hard drive it's stored on?

Intel fighting for Thunderbolt

The prospects for Thunderbolt looked rosy after it debuted in 2011, thanks to Intel's clout and support from Apple, which bet big on the technology. Thunderbolt started spreading to Windows machines in 2012. Back then, USB still maxed out at 480Mbps, about a twentieth the speed of Thunderbolt at the time.

Now more than 400 computer models support Thunderbolt, and prices of Thunderbolt-equipped computers are coming down, said Jason Ziller, general manager of Intel's Client Connectivity Division. There are about the same number of peripheral devices like storage systems, docking stations , external graphics cards and monitors, he added, double the number available a year and a half ago.

HP Spectre x360 Thunderbolt/USB-C ports

The HP Spectre x360 laptop comes with ports that work both as USB-C and Thunderbolt connectors.

Stephen Shankland/CNET

Plenty of big names are on board, like Hewlett-Packard , Lenovo and Dell . Samsung just offered a big Thunderbolt endorsement for monitors, higher-end SSD storage devices and laptops .

And Microsoft supports Thunderbolt in Windows 10 so nothing goes haywire when you plug or unplug devices and so those devices play more nicely with Microsoft's modern standby power-management technology.

Apple's Mac support continues, for example with its decision to double the number of Thunderbolt ports on the new Mac Mini to four.

Not an industry standard yet

But Thunderbolt is a proprietary Intel technology, requiring device makers to buy Intel's own controller chips to use it, which has stunted its adoption. In 2017, Intel said it planned to make Thunderbolt a royalty-free industry standard.


On the new MacBook Air, the two ports work as both industry-standard USB-C inputs and Intel's proprietary Thunderbolt alternative.

Sarah Tew/CNET

That effort ultimately could lead to other chipmakers supporting Thunderbolt and possibly bringing it to markets like phones and tablets where Intel is weak. But it's running late. Intel hoped to release the specifications in 2018, but now the plan is the first half of 2019, Ziller said.

"It's taking a little longer to do that than we expected," he said. "We're working with a group of leading companies to get them to review the specification. ... There are a lot of things they expect to be documented in a certain way to make sure they can pick up that spec without having to rely on Intel hand-holding."

Intel also hopes Thunderbolt will become more popular when it builds the technology directly into its processors. Pricing details aren't clear, but having Thunderbolt built in could help encourage PC makers worried about the power consumption, cost and complexity of standalone Thunderbolt chips.

Intel still isn't ready to say when that'll be a reality. Keep your ears open, though, for news about Thunderbolt integration in 2019, Ziller said.

Why not just use USB-C?

The bigger challenge is that Thunderbolt's advantages just don't go that far beyond USB-C. USB stands for Universal Serial Bus, and the technology has indeed attained something close to universality. It's absorbed standards younger people might've never encountered -- FireWire, SCSI, parallel, serial and PS/2 ports -- and expanded its utility to charging tablets, phones and laptops.

The USB-C version offers a better connector that works either side up, and a single port that works on laptops and smaller devices. It can handle up to 100 watts of power, enough for the highest-end laptops. It typically comes with USB 3.1's data transfer speeds of 5 or 10 gigabits per second.


The Samsung X5 SSD uses Thunderbolt for very fast data transfer. It's a premium product costing $400 for a 500GB model and $1,400 for a 2TB model.


USB-C is spreading only gradually, but it's now commonplace. Analyst firm IHS Market expects there to be nearly 5 billion devices with USB-C in 2021, a 70 percent annual growth rate.

Thunderbolt maintains a speed advantage, with 40Gbps connections that can support more or higher-resolution monitors and faster transfers for people handling thing like multigigabyte video files. But USB-C could handle 20Gbps in 2019 and could double again to 40Gbps after that. In any event, mainstream customers are generally well served even by the lower speeds for things like network cables , monitors and external storage devices.

For comparison, ordinary 4K video refreshing at 60 frames per second needs about 9Gbps of capacity.

Thunderbolt's edge

But people need more, Ziller argues. "For a lot of people, there is a need for performance and capability higher than USB," he said.

Business customers are using a single Thunderbolt cable to replace old-style laptop docks with modern docking stations. Graphic designers and photographers have to cope with "an explosion of data." And Thunderbolt lets you connect to two 4K monitors at 60fps -- while you're transferring data at the same time and perhaps connecting to an external graphics card.

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Intel is working with industry partners to try to lower Thunderbolt device prices, he added, and integration in Intel chips should cut costs manufacturers have to pay Intel. He's pushing for a "good, better, best" approach, with Thunderbolt spreading from the high end to more mainstream devices. Evidence that things are looking up: He just returned from a Thunderbolt event in Taiwan that had the most people ever, 350, for training and the most devices ever, 36, making the rounds at a "plugfest" to ensure Thunderbolt devices work properly everywhere.

Tens of millions of laptops have Thunderbolt today, Ziller said. You may not even know it, since Thunderbolt 3 uses the USB-C port itself, letting you connect more than USB-C itself accommodates. You can check for Thunderbolt's lightning-bolt logo next to the port, though it's not always there -- for example on newer Apple laptops.

But all of them have USB-C, and now Apple's iPad Pro tablets do, too. It's tough to compete with ubiquity.

Intel's publicity says "Thunderbolt 3 -- the USB-C that does it all" and urges us to "envision a world with Thunderbolt 3 everywhere." So far, though, Thunderbolt's reality falls short of Intel's hopes.

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