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USB4: Based on Thunderbolt 3. Two times the data rate, at 40Gbps. One fewer space. Zero confusing versions

We live in hope – you'll have to wait until 2020 at the earliest

USB version 4 is on the way, offering double the fastest possible USB data transfer rate over the previous generation: a satisfying 40Gbps.

On Monday, the USB Promoter Group announced the new spec is ready to be revealed, just a week after details of the latest iteration of the current standard – USB 3.2 – was released.

Note, we're talking about USB communications here: how the data is transferred over the lines, not the physical plugs and sockets. This announcement means future devices and computers can use USB4 to shove files and other information between each other much faster, typically via physical USB-C connectors.

USB4 – yes, no space – is based on Intel's Thunderbolt 3 specifications, and will allow for multiple simultaneous data and display linkages, meaning that you can use it for several different devices at the same time, and each data transfer will be adjusted dynamically between each bit of kit.

Critically, it will be backwards compatible with existing USB 2, 3 and Thunderbolt 3 specs. Because it's a USB specification, it will also be an open standard and royalty-free. This follows from Intel's promise to make Thunderbolt 3 royalty free. The chip giant will continue to tout its Thunderbolt tech until USB4 becomes a reality.

"The primary goal of USB is to deliver the best user experience combining data, display and power delivery over a user-friendly and robust cable and connector solution," said Brad Saunders, chairman of USB Promotor. "The USB4 solution specifically tailors bus operation to further enhance this experience by optimizing the blend of data and display over a single connection and enabling the further doubling of performance."

The spec will be formally published in the middle of the year, around the same time as the release of USB 3.2 kit. That means that USB4 should become available in products some time toward the end of 2020, although that's up to manufacturers.

Figure this one out

The new standard will be a welcome shift from what has become an increasingly confusing USB naming convention. USB 3.0 (max 5Gbps) is now known as USB 3.2 gen 1, while USB 3.1 (max 10Gbps) is known as USB 3.2 gen 2.

Then there's USB 3.2 (max 20Gbps) which is now known as USB 3.2 gen 2x2. In an apparent effort to be clearer, there are some new names, but they have only further confused people.

USB 3.0 aka USB 3.2 gen 1 is called SuperSpeed USB. USB 3.1 aka USB 3.2 gen 2 offers 10Gbps will be branded Superspeed USB with "10Gbps" stuck at the end. And USB 3.2 aka USB 3.2 gen 2x2 is exactly the same but with "20Gbps" on the end. Meanwhile, USB4 is SuperSpeed USB 40Gbps.

Why on earth has the USB Implementers Forum (USB IF) come up with such a terrible system? You'll have to ask them but the likelihood is some tech pedants and/or marketeers have insisted on the correct usage of versioning numbers and so confused everybody. But, in theory at least, any form of 3.2 should work with USB4, including its bus discovery, configuration and performance requirements.

Cliff Richard Wired for Sound Video

USB-C is now wired for sound, just like Sir Cliff Richard


The main driver behind USB4 has been Intel, though another 50 companies have been "actively participating in the final stages of review of the draft specification," the USB Promoter Group, which includes Apple, HP, Intel, Microsoft and Texas Instruments as members, said.

The USB4 announcement is solely for developers right now, with branding and marketing to be developed once the final spec is out. There is a less-than-zero chance that they will call it "SuperSpeed USB 40Gbps" but with any luck, since Intel's people are in the driving seat, sanity should prevail and they'll come up with a suitably over-excited term like "Hyperspeed Extreme Alpha+ USB."

"By collaborating with the USB Promoter Group, we’re opening the doors for innovation across a wide range of devices and increasing compatibility to deliver better experiences to consumers," said Intel's connectivity GM, Jason Ziller, in a statement. ®

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