USB4 Specification Merges Thunderbolt 3 and USB With Transfer Speeds up to 40Gb/s

The USB4 specification for a new version of USB was today published by the USB Implementers Forum [PDF] giving us details on what to expect from the next-generation USB architecture following a preview back in March.

USB4 is a major update that "complements and builds upon" the current USB 3.2 2x2 (USB-C) and USB 2.0 architectures. According to the USB-IF, the USB4 architecture is based on Thunderbolt, doubling the maximum bandwidth of USB and allowing for multiple simultaneous data and display protocols.


The USB-IF outlined key specifications of the USB4 architecture, such as 40Gb/s speeds (twice the current 20Gb/s maximum) and backwards compatibility with USB 3.2 and Thunderbolt 3.

  • Two-lane operation using existing USB Type-C cables and up to 40Gbps operation over 40Gbps certified cables
  • Multiple data and display protocols that efficiently share the maximum aggregate bandwidth
  • Backward compatibility with USB 3.2, USB 2.0 and Thunderbolt 3

USB4 will use the same USB-C connector design as USB 3, which means manufacturers will not need to introduce new USB4 ports into their devices.

Apple's newest Macs offer support for USB-C and Thunderbolt 3, which means most Mac users are already experiencing USB4 speeds when using Thunderbolt 3 cables and devices, but USB4 will make Thunderbolt-style speeds the new default and it will lower the cost of devices that use these faster transfer speeds.

USB Power Delivery will be required in devices built for USB4, which also means we can expect to see higher-powered chargers with multiple USB4 ports.

Though the USB4 specification is complete, it will still be some time before we can expect to see devices that take advantage of USB4. It typically takes at least a year for new products to come out following the finalization of a new specification, so it will be late 2020 or beyond before we begin seeing USB4 devices.

Top Rated Comments

(View all)
Avatar
14 months ago
One cable to rule them all.

Now lets get USB-C on an iPhone.
Score: 49 Votes (Like | Disagree)
Avatar
14 months ago

One cable to rule them all.

Now lets get USB-C on an iPhone.

Don't get me wrong, I like USB-C, but it is not the panacea everyone makes it out to be. There is not "one cable." There are a large number of different USB-C cables, all with different specs, speeds, etc.

Inexpensive USB-C charging cables are limited to USB2 speeds and most of them are limited to 30W of power. There are 60W and higher cables, but in 6ft lengths there are not as many options and it's far from easy to figure out what you're going to get. Some suppliers write the limits in terms of watts, some in terms of volts and amps. Most laymen have trouble figuring it all out.

And then there are the chargers... 18W, 30W, 60W, 90W, 100W, 5V, 12V, 18V, 2A, 3A. Chargers with two ports get even more confusing. While it's relatively easy math, I don't think having people doing Ohm's Law calculations in their heads when buying chargers in cables is user-friendly.

But I mentioned basic charging cables are super slow for data. If you want to use a USB-C cable for data, then it's even more confusing. Speeds vary depending on cable length and spec variant compatibility - a USB-C Gen 1 vs USB-C Gen 2 vs Thunderbolt 3; 1.5ft vs 3ft vs 6ft. Each combination will have a different max speed. It's all very difficult for most folks to keep straight.

Basically, USB is still a spaghetti of specs and limits, and this is just adding yet another layer. Just because the physical plug of Type C is nice, does not mean all the other USB problems are solved.
Score: 33 Votes (Like | Disagree)
Avatar
14 months ago
Congratulations Apple, you were four or five years early—you certainly earn that distinction. Too bad that the products in the meantime were entirely unflexible and annoying for anyone who wanted to conveniently use their laptop as a computer
Score: 16 Votes (Like | Disagree)
Avatar
14 months ago
I don’t even have a Mac with USBC yet..
Score: 12 Votes (Like | Disagree)
Avatar
14 months ago
Will USB4 then drop support for USB-A, B and B's little cousins mini and micro? Because if so, it's about time!
Score: 10 Votes (Like | Disagree)
Avatar
14 months ago
Lightning is still the most robust port design I've ever come across for serious charging/data capabilities. I can plug my phone in every day multiple times a day for two years and the port will still be solid enough to dangle the iPhone from its charging cable no problem. Meanwhile the USB C ports on my MacBook are stupidly loose after just a couple months of use to the point where occasionally the charger would unplug itself if you move the laptop in a strange way.

I know this is controversial but I'd much rather keep a robust port on the iPhone (lightning) than a convenient yet fragile one (USB C).
Score: 7 Votes (Like | Disagree)

Top Stories

Here's How You Can Download iOS 14 and iPadOS 14 Around the World [It's Out]

Wednesday September 16, 2020 2:36 am PDT by
Apple's official public release of iOS 14 and iPadOS 14 dropped on Wednesday, September 16, just a day after the company released the Golden Master to third-party developers. Also set to be made available to the general public for the first time are watchOS 7 and tvOS 14. Getting Started With iOS 14 Video Click image to watch iOS 14 Getting Started While that's left a lot of developers...

When Will the iPhone 12 Launch? Here's What We Know

Wednesday September 16, 2020 6:12 am PDT by
Yesterday's "Time Flies" Apple event saw the release of the Apple Watch Series 6, Apple Watch SE, iPad 8, and iPad Air 4, but no new iPhone models. Rumors before the event strongly alleged that it would not see the unveiling of new iPhones, with many reports pointing to an October launch. The lack of new iPhone models yesterday seems to confirm that the iPhone 12 lineup will not appear...

Apple Releases iOS 14 and iPadOS 14 With Home Screen Redesign, App Library, Compact UI, Translate App, Scribble Support, App Clips, and More

Wednesday September 16, 2020 12:48 pm PDT by
Apple has released iOS 14 and iPadOS 14, the newest operating system updates designed for the iPhone and iPad. As with all of Apple's software updates, iOS 14 and iPadOS 14 can be downloaded for free. iOS 14 is available on the iPhone 6s and later, while iPadOS 14 is available on the iPad Air 2 and later. The updates are available on all eligible devices over-the-air in the Settings app. To ...

Apple Releases Safari 14 for Mac Ahead of macOS Big Sur Launch

Wednesday September 16, 2020 1:40 pm PDT by
macOS Big Sur didn't launch alongside iOS 14, iPadOS 14, tvOS 14, and watchOS 7 today, with the update coming later this fall, but Apple did release the Safari 14 update for macOS Catalina and macOS Mojave users. Safari 14 brings improved performance, customizable start pages, a Privacy Report to see which cross-site trackers are being blocked, and a new tab bar design that provides tab...

Apple Updates AirPods 2 and AirPods Pro Firmware to Version 3A283

Monday September 14, 2020 11:24 am PDT by
Apple today released new 3A283 firmware updates for the second-generation AirPods and the AirPods Pro. The second-generation AirPods are being updated from the 2D15 firmware they were previously running, while the AirPods Pros are being updated from the 2D27 firmware they had installed previously. Apple does not provide details on what's included in refreshed firmware so we don't know what's ...

iOS 14 Picture in Picture No Longer Working With YouTube's Mobile Website in Safari [Without Premium]

Friday September 18, 2020 12:21 pm PDT by
Apple in iOS 14 added Picture in Picture to the iPhone, a feature designed to let you watch a video in a small screen on your device while you continue to do other things on the phone. When Picture in Picture was working with YouTube The YouTube app doesn't support Picture in Picture, but up until yesterday there was a functional workaround that allowed videos from YouTube.com to be watched...

Hands-On With the New Apple Watch Series 6 and Apple Watch SE

Friday September 18, 2020 1:19 pm PDT by
Today's the official launch date for the Apple Watch Series 6 and the Apple Watch SE, both of which Apple announced on Tuesday. We picked up a couple of the new models and thought we'd give them a quick look for MacRumors readers thinking of ordering a new watch. Apple Watch Series 6 & Apple Watch SE Hands-On! When it comes to design, both the $399 Series 6 and the $279 SE look just like...

iOS 14.2 Beta Adds New Shazam Music Recognition Feature for Control Center

Thursday September 17, 2020 3:36 pm PDT by
Apple today released the first beta of iOS 14.2 to developers for testing purposes, and the new update introduces a Music Recognition control for the Control Center. The new feature lets you discover music playing around you and it recognizes the music playing with in apps, even when you're wearing AirPods. Songs pop up as notifications, and you can tap to listen in Apple Music....

8 Third-Party Home Screen Widgets That You Can Try Out Now on iOS 14

Wednesday August 5, 2020 12:56 pm PDT by
One of the biggest new features of iOS 14 is Home Screen widgets, which provide information from apps at a glance. The widgets can be pinned to the Home Screen in various spots and sizes, allowing for many different layouts. When the iOS 14 beta was first released in June, widgets were limited to Apple's own apps like Calendar and Weather, but several third-party developers have begun to test ...

Apple Releases watchOS 7 With New Watch Faces, Family Setup, Sleep Tracking, Handwashing Help and More

Wednesday September 16, 2020 12:47 pm PDT by
Apple today released watchOS 7, the newest version of the watchOS operating system designed to run on modern Apple Watch models. The watchOS 7 update comes after several months of beta testing. ‌watchOS 7‌ can be downloaded for free through the dedicated Apple Watch app on the iPhone by going to General > Software Update. To install the new software, the Apple Watch needs to have at...