What Do USB 3.0, 3.1, and 3.2 Really Mean? What Are the Differences Between Them?

In the past, choosing the fastest USB was easy; you just had to look for USB 3.0 instead of USB 2.0.

But now, you see many products labeled as USB 3.2 Gen1, Gen2, Gen3, or Gen2×2 on the market, making it confusing for people to choose the right USB.

Now, we will guide you through the differences between USB 3.0, 3.1, and 3.2 (USB 3.2 Gen1, Gen2, and Gen2×2).

In the past, there were only two main USB versions: 2.0 and 3.0. You just needed to know that 3.0 was faster than 2.0.

You could buy a USB 2.0 flash drive and plug it into a computer with a USB 3.0 port, and it would still work fine, but it would only operate at USB 2.0 speeds.

Similarly, if you plugged a USB 3.0 flash drive into a USB 2.0 port, you would still get USB 2.0 speeds.

If you wanted to achieve peak speeds, you needed a USB 3.0 flash drive with a USB 3.0 port.

It was that simple.

But with the introduction of USB 3.1, everything changed.

First of all, there's the naming confusion with USB 3.1.

The American USB standards organization (USB-IF) is responsible for maintaining and updating USB specifications and standards, as well as providing naming schemes for USB cables and devices.

When they introduced USB 3.1, they didn't simply distinguish it from USB 3.0.

Instead, they named the new standard "USB 3.1 Gen2" and renamed the old USB 3.0 to "USB 3.1 Gen1."

What's more complex is that even the transfer speeds themselves have been renamed.

USB 3.1 Gen1 (formerly USB 3.0) can achieve a transfer speed of 5Gbps, referred to as "Super Speed." USB 3.1 Gen2 (the new USB 3.1) offers a transfer speed of 10Gbps, known as "Super Speed+."

Technically, it achieves this by using 128b/132b encoding in full-duplex mode.

Full-duplex mode means that data can be transmitted and received simultaneously, which is why it is faster.

The differences between the two can be a bit confusing, but for the average consumer, just remember that Gen2 is newer and better than Gen1, and you won't go wrong when making a purchase.

To help distinguish speeds, USB-IF uses special logos that manufacturers can use only after passing certification, proving that the cables meet the promised specifications.

USB 3.2 offers faster speeds but even more confusing naming conventions.

In September 2017, USB-IF released the specifications for USB 3.2.

With speeds up to 20Gbps, double that of USB 3.1 Gen2, it features two 10Gbps channels, which you can think of as more wires being placed inside the same cable.

Like the previous generation, this newer standard is backward compatible, but you won't achieve the faster speeds without compatible new hardware.

At MWC 2019, USB-IF announced new logos and naming schemes for the standard, with the previous names being discarded and changed once again. USB 3.0, with a transfer speed of 5Gbps, was rebranded as USB 3.2 Gen1!

The 10Gbps standard was named USB 3.2 Gen2, and the 20Gbps standard was named USB 3.2 Gen2x2, breaking the previous naming conventions.

Physically, it has two 10Gbps channels, so it is essentially 2x2.

While this naming makes sense logically, it is more confusing, requiring consumers to have a certain level of understanding of USB hardware to recognize its true meaning.

Simpler naming arrived but is not uniformly used. 

Since 2020, USB-IF no longer wants users to see these complex names.

Instead, they want first-generation products (the old USB 3.0) to be sold under the name "Super Speed USB," and they recommend manufacturers to sell Gen2 products (USB 3.1) as "Super Speed+ USB 10Gbps," and Gen2x2 (USB 3.2) as "Super Speed+ USB 20Gbps," once again unifying the naming conventions.

In 2022, USB-IF streamlined the naming convention once more, labeling the three standards as USB 5Gbps, USB 10Gbps, and USB 20Gbps, reflecting their straightforward transfer speeds.

This revised nomenclature might seem more intuitive and comprehensible, doesn't it?

However, this simplification does not impose a mandate on manufacturers to adopt these names.

Manufacturers retain the liberty to market their products with labels such as "Super Speed" or earlier Gen2.2 denominations.

If they prefer not to adhere to the USB-IF certification mark, they are free to forgo it and select any preferred moniker.

When manufacturers opt for the "Super Speed" standard, the naming complexity diminishes somewhat.

Look for the mention of "Super Speed" in the product name, along with any accompanying numerals.

If both are absent, it signifies the slowest USB 3.2 version.

The presence of "Super Speed+" coupled with either 10 or 20 signifies a transfer speed of 10Gbps or 20Gbps, respectively.

Consequently, amid the maze of naming conventions, it's crucial to scrutinize the product description thoroughly before making a purchase and prioritize reliable and dependable brands.

Comparison of USB 3.2 Gen1, Gen2, and Gen2×2 Speeds

If the device in your possession does not feature the USB-IF certification mark, we have compiled an information table for each generation, outlining its attainable speed, corresponding official logo, and alternative names.

The sole notable difference among these interface standards lies in the fact that USB 20Gbps (Gen2×2) is exclusive to USB Type-C ports and cables; thus, you are unlikely to encounter USB Type-A or Micro USB interfaces bearing this specific designation.

If, beyond speed, you're also interested in the charging power of different USB standards, here's a straightforward overview: Regardless of the generation, all USB 3.x ports support a modest 4.5W charging capacity.

While this is significantly slower than the current slowest mobile fast-charging speed of 18W, it's still considerably faster than the 2.5W offered by USB 2.0.

Therefore, if you have the choice between a USB 2.0 and a 3.2 port for charging your device, consistently opt for the 3.2 port, albeit with tempered expectations.

USB 3.2 will no longer have new members.

I understand it might seem a bit complicated.

But here's some good news: The era of USB 3.2 is coming to an end, and it will soon be replaced by USB 4 technology, which surpasses USB 3.2 in terms of data transfer speed and charging power.

Most importantly, USB 4 was introduced after the Super Speed logo, making it much simpler to choose the right cable compared to USB 3.2. 

I am Charlie Wu.

Thank you for your reading!