USB4 spec is coming to clear up confusion and again double the speed of USB

Intel via Tim Herman. Click for original.

(Image: © Intel via Tim Herman)

The advent of USB as a ubiquitous connection standard is one of the best things to happen to the PC. Though more recently, spec upgrades and convoluted rebranding efforts have taken something awesome and made it frustrating. That might change when USB4 arrives.

USB4 promises to bring sense to what has become a nonsensical mess of specs, features, and connection types. The USB Promoter Group, the standards body in charge of the USB specification, has formally introduced the USB4 specification in draft form today, with hopes of finalizing the standard within the next few months.

So, what exactly makes USB4 so promising? For one, it will again double the speed of USB, from 20Gbps recently introduced in USB 3.2 Gen 2x2, to 40Gbps via two-lane operation over certified cables.

Beyond the raw speed increase, though, USB4 ditches the Type-A connector that dominates the landscape and wholeheartedly embraces Type-C, which is a smaller and reversible connector as shown in the image at the top of this article. USB4 is both a speed and connection standard.

USB4 also integrates Thunderbolt 3 into the spec. This is a big deal because the way things stand, it's not always clear if a USB-C port is also a Thunderbolt port. Intel designed Thunderbolt back in 2011 and, over time, it came to work over USB-C.

As of Thunderbolt 3, Intel has made the spec available royalty free, and the USB Promoter Group is pouncing by officially injecting it into USB4. So, all USB4 devices and ports will support Thunderbolt devices.

"The convergence of the underlying Thunderbolt and USB protocols will increase compatibility among USB Type-C connector-based products, simplifying how people connect their devices," Intel said.

This all may still sound confusing, but it's really only because of the current situation. Introducing USB4 is sort of like hitting the reset button on USB. There is just one connector (Type-C), it supports Thunderbolt, and there is just one version rather than Gen 1, Gen 2, and Gen 2x2. It's basically a consolidation of specs and branding.

Why it couldn't be called "USB 4" (with a space) versus "USB4" (no space) is another question, but if it ultimately makes things less confusing in the long run, we'll give the USB Promoter Group a pass.