USB 3.0 vs. 3.1 - What's the Difference?

The universal serial bus, or USB, has been a stalwart connector for all sorts of devices and systems for almost thirty years. It's consistently kept pace with new demands for speed and features, and today is one of the most comprehensive connectors out there. That does depend on which version of USB you make use of, though, with older generations not offering the same capabilities as the latest. While USB4, Thunderbolt 4, and other USB-C type connectors might be the most capable and popular today, there is still some life in older generations of USB.

Two of the most standout generations of USB in recent years have been USB 3.0 and USB 3.1. Although they were eventually supplanted by USB 3.2 in all its forms, and USB4 beyond that, USB 3.0 and 3.1 devices are still incredibly common, and most desktop computers are still released with a number of USB-A 3.0 connectors.

But how do these types of USB connectors compare? When it’s USB 3.0 vs 3.1, where do these generational standards differ?

The difference between USB 3.0 and 3.1 isn't drastic, but it can make a big difference depending on the devices you own and what you want to do with them. Here's how USB 3.1 vs USB 3.0 fare against one another.

Naming confusion

Before addressing the main USB 3.0 vs 3.1 debate, it's important to clear up what's being discussed. The organization that promotes and supports USB development, the USB Implementers Forum, retroactively renamed all third-generation USB connections at the release of USB 3.2.

Technically, USB 3.0, 3.1, and 3.2, are now all known as USB 3.2. To avoid confusion, manufacturers describe their USB products in terms of speed: SuperSpeed USB 5 Gbps, SuperSpeed USB 10 Gbps, or SuperSpeed USB 20 Gbps, depending on the USB version they support. Bear that in mind when buying USB-compatible devices.

Cable Matters takes this naming convention in mind, and where necessary, uses both the traditional USB namings and labels cables with the maximum speeds they can handle. That said, it's important to note that when it comes to third-generation USB cables, they are fully compatible with themselves and USB 2.0 ports - but can only operate at the fastest speed of the oldest generation USB part in the chain. So a USB 3.2 Gen 1 cable plugged into a USB 2.0 port will only be able to operate at USB 2.0 speeds.

The USB cable must still match the port it’s going into, though. So only USB-A cables are compatible with USB-A ports, regardless of generation. All USB-C cables and ports are inter-compatible and can work with USB-A ports when using an adapter or conversion cable. 

This is actually one of the most useful features of newer USB-C cables. Whether they’re from the USB4 family, the older USB 3.2 Gen 2x2, or one of Intel’s Thunderbolt 3 or 4 cables. All of them, as long as they have the USB-C header, will work together. They’ll only operate at the speed of the slowest element in the chain, but if the plug fits, they will work. 

The difference between USB 3.0 and 3.1

The core difference between USB 3.0 and 3.1 is the transfer speed. When it was introduced in 2008, USB 3.0 revolutionized USB bandwidth. USB 3.0 increased the maximum transfer speed to 5Gbps – working out to around 500MB/s in the real world – using its new SuperSpeed transfer mode, a nearly 10-fold increase over its predecessor, USB 2.0.

To differentiate this higher-speed connector from older USB ports and devices, cables were equipped with a specific SuperSpeed logo, and the ports themselves were often colored blue.

USB 3.1 arrived five years later and upped the ante again, raising the maximum transfer speed to 10Gbps using the SuperSpeed+ transfer mode. USB 3.1 Gen 2 is fast enough to drive even 10 Gigabit Ethernet connections.

Since the debut of USB 3.1, USB-IF decided to abandon the USB 3.0 name and use USB 3.1 Gen 1 to replace USB 3.0, both of which support 5Gbps transfer speed.

The USB 3.1 vs USB 3.0 difference remains almost exclusively bandwidth dependent. Both connectors operate the same whether using a more traditional USB-A or USB-B, or any of the various micro and mini USB connectors. Their generation is what's important, not the connector header.

That goes for USB-C connectors too, although you'll typically find USB-C devices support the faster USB 3.1, or even 3.2 standards- not always though. Many USB-C cables marketed as charging cables only support USB 3.0 or even 2.0 speeds. 

While USB 3.1 clearly wins the speed battle over USB 3.0, their successor outclasses both of them.

USB 3.2 and the future

The 3.0 vs 3.1 USB debate was settled for good with the release of USB 3.2. It preserved the existing SuperSpeed and SuperSpeed+ transfer modes of its predecessors and doubled the data transfer channels from a single lane to two lanes, doubling the max transfer rate to 20 Gbps.

Again, the USB 3.1 Gen 1 / Gen 2 naming convention became obsolete and was replaced by USB 3.2 Gen 1 / Gen 2

Full 20Gbps speeds are only possible with a USB-C cable, owing to the cable’s additional wires and pins, but USB technology didn't stop there. 

Since the release of USB 3.2 Gen 2x2 USB-C cables, a new generation of USB4 cables was launched, introducing even higher data rates, advanced features, and improved compatibility with Intel’s Thunderbolt standard. Based on the Thunderbolt 3 protocol, USB4 improves maximum cable bandwidth to 40 Gbps – double that of the best USB 3.2 Gen 2x2 cables. It also adds official support and compatibility with Thunderbolt 3 and is supported in turn by Thunderbolt 4, so the latest generations of USB-C cabling are almost completely interchangeable.

However, where Thunderbolt 4 mandates a 40 Gbps transfer speed, that’s not always the case with USB4. Although it can support it, not all cables do, so the USB Forum has introduced a new USB 40Gbps logo and certification, so that compatible cables are clearly marked and marketed.

USB4 also supports DisplayPort 2.1 tunneling, so can transmit video and audio from a source device to a USB4-compatible display. That gives USB4 the ability to support very high-resolution monitors, like 8K, and also UHD displays with high refresh rates, like 4K 144Hz.

USB Power Delivery was boosted with this new generation of USB, too, with the latest cables able to transmit up to 100W of power. That makes it possible to quickly charge even big and bulky devices like gaming laptops, as well as tablets and other devices larger than a smartphone. 

Some of the highest quality USB4 cables can even offer up to 240W of charging power, making them the fastest, most powerful USB chargers ever created.

That was just the first generation of USB4, though. The USB Implementers Forum has announced a USB4 2.0 specification that will raise the bandwidth again to a maximum of 80 Gbps for bi-directional data transfers, or up to 120 Gbps when only sending data in one direction, such as streaming video. That has the potential to open up even higher resolutions and refresh rates, although no devices or cables yet exist which can take advantage of these ultra-high specifications.

Conclusion – are USB 3.0 and 3.1 still relevant?

The USB 3.0 vs 3.1 debate might be all but settled, and these technologies might have been superseded by younger, more capable solutions, but there’s still plenty of space for USB 3.0 and 3.1 to remain relevant. Many legacy devices that use USB-A 3.1 and 3.0 connectors for power and data transfer are still out in the wild, and most PC peripherals like mice, keyboards, and webcams, still use USB-A as their primary connector type. Considering desktop PCs continue to offer many USB-A ports to provide legacy support for these devices, too, it’s likely that we’ll see USB 3.0 and 3.1 around for many years to come.

That said, they have been thoroughly supplanted in every way, with the latest generations of USB4 and Thunderbolt cables and ports offering much higher performance numbers, and much better feature lists. Look for these older USB-A connectors and cables to be gradually replaced in the years to come.

In the meantime, though, you can grab high-quality USB-A cables right here at Cable Matters, and we stock a wide range of USB-C and other cable types too. Whatever you need, we’re sure to have it.