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.
Popular Stories
While the iPhone 17 Pro and iPhone 17 Pro Max are not expected to launch until September, there are already plenty of rumors about the devices.
Below, we recap key changes rumored for the iPhone 17 Pro models as of March 2025:
Aluminum frame: iPhone 17 Pro models are rumored to have an aluminum frame, whereas the iPhone 15 Pro and iPhone 16 Pro models have a titanium frame, and the iPhone ...
If you pay for iCloud storage on your iPhone, Apple has a new perk for you, at no additional cost.
The new perk is the ability to create invitations in the Apple Invites app for the iPhone, which launched in the App Store last month.
In the Apple Invites app, iCloud+ subscribers can create invitations for any occasion, such as birthday parties, graduations, baby showers, and more. Anyone ...
Apple is expected to release iOS 18.4 to the general public as soon as next week, following more than a month of beta testing.
Apple's website says some iOS 18.4 features will be released in "early April," so the update should be out as early as Tuesday, April 1.
Apple this week seeded the iOS 18.4 Release Candidate, which is typically the final beta version, barring the discovery of any...
Apple today seeded the release candidate versions of upcoming iOS 18.4 and iPadOS 18.4 updates to developers for testing purposes, with the software coming a week after Apple released the fourth betas.
iOS 18.4 and iPadOS 18.4 can be downloaded from the Settings app on a compatible device by going to General > Software Update.
With iOS 18.4, Apple is adding the Priority Notifications...
Apple today announced that AirPods Max with a USB-C port will be gaining support for lossless audio and ultra-low latency audio with a firmware update next month, alongside the release of iOS 18.4, iPadOS 18.4, and macOS 15.4.
For context, audio files are typically compressed to keep file sizes smaller. There are lossy compression standards like MP3 and AAC (Advanced Audio Codec), which...
We're not getting new Siri Apple Intelligence features in iOS 18.4 as expected, but the upcoming update does have quite a few new additions that will be worth upgrading for. We've rounded up the five best features to look forward to, and if you're not running the beta, you can expect to get access to these in early April.
Priority Notifications
If you have an iPhone or iPad that supports...
Apple will launch its long-rumored foldable iPhone next year with a ~$2,000 premium price tag attached, expects well-connected Bloomberg reporter Mark Gurman.
Gurman's comments on Apple's launch plans for its first foldable device appeared in the Q&A section of his latest Power On newsletter. Earlier this month, the reporter said Apple's foldable iPhone could be arriving "as early as 2026,"...
Leaker Jon Prosser today shared a mockup of what he says the Messages app will look like in iOS 19, demoing an interface with rounded, translucent bubble-shaped navigation buttons at the top and softer, rounder corners for the keyboard and word suggestions.
Jon Prosser's Messages app mockup
The return button, a button for going back to the Messages list, and the FaceTime button have a deeper...
