Understanding USB Standards: A Comprehensive Guide to Generations 1, 2, & 2X2 - Decoding USB 3.2

Quick Links

• USB Naming Used to Be Simple
• USB 3.1 Muddied the Naming Waters
• USB 3.2 is Even Faster and More Confusing
• Simpler Branding Is Here (But Not Always Used)
• Comparing USB 3.2 Gen 1 vs. Gen 2 vs. Gen 2x2 Speeds
• There Won’t Be Anymore USB 3.2 Generations

Key Takeaways

• USB Gen 1, Gen 2, and Gen 2x2 are generations of USB 3.x that have speeds of 5 Gbps, 10 Gbps, and 20 Gbps, respectively (regardless of the version number).
• USB 3.2 generations have regularly been renamed over the years, but they now simply bear the speed: USB 5 Gbps, USB 10 Gbps, and USB 20 Gbps.
• Manufacturers may not use current official branding, so read labels closely before buying hardware.

Finding the fastest USB connection used to be easy: choose USB 3.0 instead of 2.0. But now, you’ll need to know the difference between USB 3.2 Gen 1, Gen 2, and Gen 2x2—and what various types of “SuperSpeed” mean, too.

USB Naming Used to Be Simple

Once upon a time, USB came in two main flavors, 2.0 and 3.0. All you needed to know about them was 3.0 was faster than 2.0. You could buy a USB 2.0 flash drive and plug it into a computer that had USB 3.0 slots, and it would still work—just at the slower USB 2.0 speeds. Buying a USB 3.0 drive and plugging it into a USB 2.0 port would give you USB 2.0 speeds, too.

If you wanted the fastest speed possible, you’d get a USB 3.0 drive and plug it into a USB 3.0 USB port. It was simple and straightforward. But everything changed with USB 3.1.

USB 3.1 Muddied the Naming Waters

Jason Montoya / How-To Geek

The USB Implementors Forums (USB-IF) maintains USB specifications and compliance, and it’s behind the naming schemes found on USB cables and devices. When it introduced USB 3.1, rather than keep things simple and let that name differentiate from USB 3.0, it called the new standard “USB 3.1 Gen 2.” USB 3.0 was retroactively renamed “USB 3.1 Gen 1.”

To further complicate things, the transfer speeds themselves received names. USB 3.1 Gen 1, originally known as USB 3.0, is capable of 5 Gbps transfer speeds—that’s called SuperSpeed.

USB 3.1 Gen 2 is capable of 10 Gbps transfer speeds—that’s called SuperSpeed+. Technically, it accomplishes this by using 128b/132b encoding in a full-duplex communications mode. Full-duplex communication is exciting because that means information can be transferred and received at the same time. That’s why it’s faster.

The difference between the two was slightly confusing. But, as long as you remembered Gen 2 was better than Gen 1, you were good to go. To help differentiate the speeds, USB-IF also implemented logos, which manufacturer can only use by passing a certification to prove a cable matches the promised specs.

USB 3.2 is Even Faster and More Confusing

Jerome Thomas / How-To Geek

In September 2017, the USB-IF announced the USB 3.2 specification. USB 3.2 is capable of 20 Gbps speeds. That’s double the transfer speeds of USB 3.1 Gen 2. If you’re wondering how the cables are doubling their speed without changing size or connectors, it’s straight-forward. USB products capable of 20 Gbps have two 10 Gbps channels. Think of it as more wiring jammed into the same cable.

Just like in previous iterations, this newer standard is backward compatible for basic usage—but you won’t get the faster speed without all new hardware. If you buy a hard drive that promises a 20 Gbps transfer rate and plug it into an older computer, the hard drive will work, but at slower speeds than the USB ports on your machine can provide. You’ll have to update both ends of the connection to enjoy all the new benefits.

At Mobile World Congress 2019, the USB-IF announced the branding and naming schemes for the new standard. And once again, the previous naming were discarded and changed retroactively. Going forward, what had been USB 3.0, with 5 Gbps transfer speeds, would become USB 3.2 Gen 1. USB 3.1 Gen 2, with its 10 Gbps speeds, would be renamed to USB 3.2 Gen 2.

The 20 Gbps standard would be named USB 3.2 Gen 2x2, breaking the predictable pattern. Physically, this has two 10 Gbps channel, so it literally is 2x2. There’s a logic to the name, but it’s confusing, and you have to understand the hardware to realize it makes any sense.

Simpler Branding Is Here (But Not Always Used)

Hannah Stryker / How-To Geek

Starting in 2020 , USB-IF announced it didn’t want consumers to see these terms. Instead, it wanted Gen 1 products marketed as SuperSpeed USB. It suggested manufacturers market Gen 2 products as SuperSpeed+ USB 10 Gbps and Gen 2x2 as SuperSpeed+ USB 20 Gbps. This was an improvement, but still not foolproof. Luckily USB-IF further simplified the recommended nomenclature in 2022 to simply state the speed: USB 5 Gbps, USB 10 Gbps, and USB 20 Gbps, respectively. Easy, right?

But that doesn’t mean manufacturers have to use these names. Manufacturers can use the SuperSpeed or older Gen 2.2 nomenclature—or if they don’t bother to submit to testing and compliance, they can forgo the logos and use any name they feel like.

When manufacturers use the SuperSpeed standard, the naming issue is at least somewhat straightforward. Look for “SuperSpeed” in the name and check if there’s a number. If you don’t see one, it’s the slowest USB 3.2 type. If you see “SuperSpeed+” and a 10 or a 20, that’s the promise of 10 Gbps or 20 Gbps transfers. As seen in the image below, the SS and 10 denote that USB port as a SuperSpeed port capable of 10 Gbps transfers. Branding for the newer SuperSpeed+ USB 20 Gbps uses the same logo, just with a 20 in its place. At least it’s fairly straight forward .

Jordan Gloor / How-To Geek

If you remember USB-C’s early issues , this will probably seem very familiar. Read carefully before buying cables, and buy them from reputable, trusted sources. In the past, we’ve recommended Amazon Basics cables—but even with those you still need to look carefully. For instance, this Amazon Basics cable is USB-C but only offers 2.0 speeds. This Amazon Basics cable , which looks practically the same, offers 10 Gbps transfers and is marked as USB 3.1 Gen 2. And, of course, this doesn’t just apply to USB cables. It applies to any piece of hardware that uses USB-C.

Comparing USB 3.2 Gen 1 vs. Gen 2 vs. Gen 2x2 Speeds

In case your hardware isn’t using USB-IF’s current recommended branding, we’ve put together a table of information on each generation, what speeds it can achieve, other names the generation has had.

If you’re wondering about power delivery in addition to speed, that’s pretty simple: regardless of generation all USB 3.x ports deliver a humble 4.5W in charging capabilities. That’s a far cry from the 18W required for fast charging your phone, but it’s at least better than USB 2.0’s 2.5W of juice. So if you have the choice between a USB 2.0 and 3.2 port for charging a device, you’ll always want the 3.2 port (but don’t expect too much from the little guy).

The only other significant difference between these generations is that USB 20 Gbps (Gen 2x2) is limited to USB Type-C ports and cords. You won’t see any USB Type-A or Micro USB connections sporting that label.

There Won’t Be Anymore USB 3.2 Generations

The good news is that the revisions are over for the USB 3.2 and all its variations. They’ve been superseded by the likes of USB4 , which trounces USB 3.2 in terms of transfer speeds and power delivery. On top of that, it was introduced after the arrival of the SuperSpeed branding, so choosing the right cable is far simpler than USB 3.2 ever was.

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