The USB Implementers Forum (USB-IF) today released a description of the next version of USB. This brings welcome improvements in data transfer speeds, and USB 3.2 also attempts to remedy some of the confusion the public experiences trying to understand what USB products offer.
USB 3.2: Everything old is new again
First off, USB 3.1 Gen 1 and Gen 2 are being renamed USB 3.2 Gen 1 and Gen 2. These will still offer 5 Gbps and 10 Gbps data transfer speeds, respectively, so this is just a change of names. Any company making a cable with either version of USB 3.1 can rename it to the appropriate version of USB 3.2.
The big change the USB-IF announced today is USB 3.2 Gen 2×2, which offers 20 Gbps. It does so with two 10Gbps data transfer channels, which is possible with some already-available USB-C cables.
This is in keeping with one of the major goals of USB 3.2: backward compatibility. All current products will work, even if they can’t take advantage of the new capabilities.
A USB connector isn’t the same as a USB standard
One of the reasons people get confused is they expect there to be separate types of connector for the different USB standards. It doesn’t exactly work like that.
It’s true that USB Type-C cables are usually needed for the most recent USB standards, but there dosn’t have to be an obvious physical difference between a cable that supports USB 3.1 Gen 1 and one that supports Gen 2. Some cables that launched supporting USB 3.1 Gen 2 will now offer USB 3.2 Gen 2×2.
Worst of all, many companies simply brand their products as USB-C, leaving buyers guessing about which USB standard they support.
Apple usually tries to make it clear which version its computers support. Every iMac and MacBook Pro since 2017 supports USB 3.2 Gen 2, for example. So does the MacBook Air released in 2018. The 2015 MacBook has USB 3.2 Gen 1. The 2018 iPad Pro supports USB 3.2 gen 2.
Many of these devices also support Thunderbolt 3, a related but different standard that also runs over USB-C cables… just to make things more confusing.
Hoping for clearer descriptions
One of the goals of the USB-IF in this emerging standard is getting hardware makers to be more clear about what customers should expect from the USB cables, etc. they’re buying. “When referring to a product that is based on and compliant with the USB 3.2 specification, it is critical for manufacturers to clearly identify the performance capabilities of that device,” they said in the description of this standard.
For this reason, the Implementers Forum created marketing names for the versions of the standard. USB 3.2 Gen 1 is supposed to be called SuperSpeed USB while USB 3.2 Gen 2 should be dubbed SuperSpeed USB 10Gbps. USB 3.2 Gen 2×2 products should bear the name SuperSpeed USB 20Gbps.
That said. this group has no power to enforce these recommendations. It’s entirely up to hardware manufacturers to use these names on their cables, etc. And some companies have already said they prefer SuperSpeed Plus, Enhanced SuperSpeed and SuperSpeed+ for the three versions.
