What’s The Difference Between USB Generations?
The difference between USB generations comes down to device charging capabilities and data transfer speeds. We touched on both in our post USB Type-C and USB 3.1/3.2 Explained, but with so much to unpack and decode about the naming convention and capabilities of USB, we wanted to further break down the data transfer capabilities of the most recent USB generations.
The USB Implementer’s Forum and USB Naming
First thing’s first, the USB Implementer’s Forum, or USB-IF, is the organization who has named and maintained the Universal Serial Bus (USB) standard since its third generation, USB 3.0, launched in 2008. And that’s really where our story begins. Each new generation brought new features, but the primary differentiator, much like the evolution of the PCIe standard (more on that in another video on our channel), is data transfer speed.
USB 3.0, which eventually came to be known as USB 3.1 Gen 1, has a data transfer speed of 5 gigabits per second. USB 3.1 Gen 2 doubled the speeds, allowing for transfers at 10 gigabits per second. At the time, the USB-IF attempted to push the terms SuperSpeed and SuperSpeed plus to refer to USB 3.1 Gen 1 and Gen 2 respectively. You may still see that nomenclature or those logos out there, but it never really took off.
Flash forward to 2017 and the launch of USB 3.2. While this was another exciting step up in capabilities for the standard, it was also a particularly confusing period for users. Up to that point in time, new USB generations had all been launched using USB-A connectors. USB 3.2 was the first generation to take advantage of all of the capabilities provided by the newer USB-C connector, including the potential for higher transfer speeds and faster charging thanks to additional lanes built into USB-C connections for data and power to travel on. As such, USB 3.2 is available in 4 variations. And this is where a visual table really starts to come in handy.
The Key Differences Between USB Generations
USB 3.2 Gen 1×1 has the same transfer speeds as USB 3.1 Gen 1, 5 gigabits per second. USB 3.2 Gen 1×1 can utilize USB-A, USB-C and microUSB interfaces. The newly added “by 1” indication here, represents the number of data lanes available.
USB 3.2 Gen 1×2 bumps the potential transfer speed up to 10 gigabits per second thanks to an additional data lane, but as such is only available in USB-C form factor.
USB 3.2 Gen 2×1 allows for those 10 gigabit transfer speeds in the USB-A, USB-C and microUSB form factors.
And finally, USB 3.2 Gen 2×2 offers the potential for 20 gigabit per second transfer speeds, but again is only available through USB-C connections.
The Future of USB
So, what’s next? Hopefully some clarity and a healthy dose of consolidation. The standard for USB4™ was published in late 2019 and the first devices with USB4 capabilities started hitting shelves near the end of 2020. As far as OnLogic products go, it will likely take a bit longer for USB4 to make an appearance in the industrial market, but when it does it will bring with it up to 40 gigabit per second transfer speeds.
Still have questions about USB, or need to know which OnLogic hardware supports which USB transfer speed? You can find details about each computer’s capabilities on our website, or you can contact us to talk about your project and find the right connectivity standard for your needs.
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