Apple brings USB 4 to its Mac line as it unveils computers with its own M1 chips

USB 4 is going to help your PC, phone and gadgets get along.

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.
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  • 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
4 min read

Apple's new Macs feature its homegrown M1 chips and USB 4 ports.

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USB has come a long way since its humble origins as a better port for plugging your mouse or printer into your PC. Now, the latest generation of the technology standard, USB 4, is starting to show up in the wild. 

On Tuesday, Apple unveiled a portfolio of new Macs that feature USB 4 ports as it transitioned to computers running its homegrown M1 Apple Silicon chips. USB 4 is also coming to the Windows world as Intel's Tiger Lake chips roll out.

Watch this: New M1 Macs are a huge shift for Apple

USB 4 offers data transfer at up to 40 gigabits per second, double USB 3.2 speeds. It has other improvements, too, because USB is swallowing up technology from Thunderbolt, a competing premium format that Intel decided to share freely.

"We get the one connector that works with everything, offers high-end performance and works not just on high-end systems," the premium niche that Thunderbolt never escaped, said Technalysis Research analyst Bob O'Donnell. "In the end, life will get much easier for everybody."

There are lots of details, nuances and even confusion about what exactly USB is and isn't. Let's shed some light.

What kind of speed boost will we get out of USB 4?

Today's devices usually have USB 3 speeds: 5Gbps, 10Gbps and the newest, 20Gbps. USB 4 will reach 40Gbps. That's useful for data-heavy tasks like editing video that's stored on an external hard drive or using a couple of 4K monitors. USB 4 should also improve docking stations that use a single port on your laptop to connect to monitors, drives, network cables and other devices.

But not every device will hit that 40Gbps maximum. For example, phones may only support slower speeds, which is generally OK since you aren't plugging them into multiple monitors and other devices.

But there's more than just speed?

Yes. The Thunderbolt technology that USB 4 will incorporate is adept at juggling both video that's needed to run external monitors or TVs , and data that's exchanged with external drives, flash card readers and other devices. "We now can have multiple displays running simultaneously and multiple data applications at the same time," said Brad Saunders, chairman of the USB Implementers Forum -- USB-IF -- that governs the technology.

In addition, USB 4 will be powerful enough to let you plug external graphics cards into your laptop, like you can today with Thunderbolt. That's useful for gamers, video editors and photographers who want more graphics power than laptop graphics chips can provide.

I thought I knew what USB is -- a way to connect peripherals to my laptop and to charge my phone. But you said there's confusion. What is it?

It's that, but it's more, because USB has different facets.

Both USB 3.2 and USB 4 govern how devices identify themselves and send signals to each other -- the equivalent of "Hi, I'm an external hard drive and I can exchange data at 10Gbps."

Lifepowr Car Charge-a-lot 60W USB-C car charger

USB Power Delivery, combined with the USB-C connector, enables products like this Lifepowr Car Charge-a-lot car charger that can provide your laptop or phone with a hefty 60 watts of power.

Stephen Shankland/CNET

But there are two separate standards you should know about. First is USB-C, which defines a newer physical connector that's much more convenient, versatile and powerful than the old-style USB-A ports on laptops and USB Micro-B common on older Android phones. USB-C can carry heavier electrical power loads and brings the same connector to laptops, phones and higher-end Apple iPads.

Then there's USB Power Delivery, which governs how devices can send or receive electrical power. For example, a high-end laptop could tell a USB battery pack that it can use USB PD's maximum power level of 100 watts. Or an interconnected phone and tablet could negotiate with each other to figure out the tablet should charge the phone. USB, USB-C and USB PD are the future of the technology.

Read more: The best USB-C PD chargers of 2019  

Will USB 4 tidy up this USB-C and USB PD mess?

Significantly. All USB 4 connections will require USB-C connectors and will support USB PD, Saunders said. Legacy devices will linger on the market, but the USB 4 generation shouldn't require detailed scrutiny of product boxes to be sure things will get along with each other.

How will USB and Thunderbolt get along? Will I be able to plug my Thunderbolt drive into my laptop's USB 4 port?

USB 4 is getting a version of Thunderbolt 3 built in, and hardware makers can choose to support it. They'll even be able to certify it works through the USB trade group, Saunders said. That means they won't have to make an extra step to the Thunderbolt group. (Thunderbolt adopted the USB-C connector with the Thunderbolt 3 generation, so the physical connection problem already has been solved.)

However, device makers using USB 4 aren't required to support Thunderbolt. So if using today's Thunderbolt devices is important to you, check the fine print on your next PC.

The first Thunderbolt cables were expensive "active" products that needed built-in chips. Will USB 4 be the same?

No. According to Saunders, most USB 4 cables will be cheaper passive cables up to about 0.8 meter (a bit over 2.5 feet). Active cables will be an option for people who need something longer.

What's the future of Thunderbolt?

That's unclear. Intel expects the Thunderbolt brand and its certification processes will continue. The company didn't comment on whether some faster or more capable version is in the works.

HP Spectre x360 Thunderbolt/USB-C ports

Thunderbolt 3 ports, like these on a HP Spectre x360 laptop, can be marked with Intel's lightning-bolt logo. Thunderbolt 3 uses the USB-C connectors that will be required for USB 4.

Stephen Shankland/CNET

But even a more powerful Thunderbolt might not dramatically improve its prospects. USB has been catching up to Thunderbolt's power for years, and USB 4 is the most capable version yet. Staying head and shoulders above USB 4 would mean creating a more advanced version of Thunderbolt that would likely appeal only to the highest end of the market, by definition a relatively narrow niche.