USBs have been a real game changer for the world of technology, and they’ve been constantly evolving since the introduction of USB 1.0 in 1996.
Talking about the changes, each generation of USB 3 brought noticeable improvements, which were generally well received by users. The naming convention on the other hand, was a disaster.
Both the official and marketing names were revised multiple times. For instance,USB 3.0was renamed asUSB 3.1 Gen 1, and renamed again asUSB 3.2 Gen 1×1. While the latter is the currently used name, some people still prefer the older names, which adds to the confusion.
If you’re (understandably) confused as well, the table below should be helpful.
For ease of reading, we’ve organized the sections below in chronological order with the current generation-based naming convention, i.e.,USB 3.2 Gen 1×1, 2×1, and 2×2.
USB 3.2 Gen 1×1 (USB 3.0)
USB 3.2 Gen 1×1, originally introduced as USB 3.0 in November 2008, had severalsignificant improvements over USB 2.0, its predecessor.
The revised USB 2.0 standard supported all types of connectors from Type-A to Mini-AB. USB 3.0 dropped support for the mini connectors and instead supportednew versions ofType-A, Type-B, Type-C, Micro-A, Micro-B, and Micro-AB connectors.
The USB 3.0 Type-A connectors were backward compatible with the USB 2.0 version. However, this isnot the casefor the rest of the connectors, as the other versions don’t physically match. You’ll need an adapter to use these USB 3.0 connectors with a USB 2.0 port.
With these connectors, USB 3.0 specified 150 mA or0.6 Wcurrent for one unit load devices, and up to 900mA or4.5 Wfor max six load devices at5 V. Additionally, USB 3.0 ports could bump the available current up to 1.5 A or7.5 Wif implementing the USB Battery Charging Specification.
And most importantly, USB 3.0, which was marketed as SuperSpeed, introduced max transfer speeds of up to5 Gbit/s, a massive 10x increase from USB 2.0’s Hi-Speed USB.
USB 3.2 Gen 2×1 (USB 3.1)
USB-IF introduced the USB 3.1 standard in 2013, and this is where the rebranding mess began. USB 3.0 was renamed to USB 3.1 Gen 1, while USB 3.1 was marketed as USB 3.1 Gen 2, or SuperSpeed +.
USB 3.1 Gen 1 superseded USB 3.0, meaning it had the same specs, with 5 Gbit/s max bandwidth over a single lane using 8b/10b encoding.
USB 3.1 Gen 2 improved on these specs with a new max data transfer rate up to10 Gbit/swith128b/132b encoding. Of course, this was only a theoretical max. But the real-world max speeds were still very impressive at over7Gbit/s.
While the connector types didn’t change from USB 3.0 to 3.1, one significant difference was the use ofUSB Power Delivery (PD)standard. The revised USB PD Rev 2.0 standard was released as part of the USB 3.1 suite, whichupdated USB PD to support various USB-C featuressuch as Alternate Mode.
In terms of power, USB PD introduced Power Rules which defined normative voltage levels at5 V,9 V,15 V, and20 V. Fixed power profiles were also dropped, meaning power supplies could support maximum source output power ranging anywhere from0.5 Wto100 W.
USB 3.2 Gen 2×2 (USB 3.2)
USB-IF released USB 3.2 in August 2017, and this is where the naming convention really became an issue. USB 3.0, which was rebranded as USB 3.1 Gen 1, was absorbed by USB 3.2 and once again rebranded as USB 3.2 Gen 1×1.
This can get confusing, but as one of our readers put it, thinking of anything referring to Gen 1 as 3.0 could be an easy way to remember.
Similarly, USB 3.1 was renamed as USB 3.2 Gen 2×1, while USB 3.2 was branded asUSB 3.2 Gen 2×2. The old marketing names, SuperSpeed and SuperSpeed + were also changed to SuperSpeed 5 Gbit/s and SuperSpeed 10 Gbit/s. Following this trend, the marketing name for USB 3.2 wasSuperSpeed 20 Gbit/s.
As evident from the brand name, USB 3.2 operates with dual-lane differential SuperSpeed pairs and uses128b/132b encodingto offer max speeds of up to20 Gbit/s.
Another very noticeable change with USB 3.2 was that it deprecated all connector types aside from theUSB Type-Cconnector. USB-C specifies a symmetrical connector with 12 A pins on top and 12 B pins at the bottom. Because of the rotational symmetry, you needn’t worry about the correct orientation as with other connector types.
The exclusive use of USB-C meant that the implementation of features such asAlternate Modewas also much more prevalent with USB 3.2. For instance, with the DisplayPort alt mode, you couldtransfer both USB and Video datasimultaneously.
USB 3.0 Vs 3.1 Vs 3.2 – Main Differences
To recap, here are the main differences as detailed in the sections above:
Aside from these major technical differences, there are a few more things worth talking about, starting with the pricing. Each iteration of USB 3 saw the use ofimproved technology, which subsequently meantincreased product priceson the customer’s end.
The exact price difference between the generations differs according to the product, but you can always count on the newer generation products with better specs to cost higher than the older ones.
Second, is the matter of appearance.USB 3.0originally usedbluecolored ports, whereasUSB 3.1adaptedtealcolored ports instead. Some manufacturer’s also use purple or violet for USB 3.1 ports.
While in previous iterations of USB,redcolor was adapted on those ports/connectors which waslimited to charging,USB 3.2 Gen 2×2 adapted this color wholly.
Finally, let’s talk about actual implementation. With how immensely popular the USB standard is, implementing a new version worldwide is a herculean task that takes years. USB 2.0 had 8 years to establish itself as a standard.
On the other hand, USB 3.0 only had around 4 years between its introduction and the release of USB 3.1. It’s the same story with USB 3.1 and USB 3.2. In fact, USB 3.2 was the likely the least popular, as by the time it’s implementation actually began in 2019, USB4 was already introduced.
USB4 And The Future
USB4, which is based on the Thunderbolt 3 protocol, is currently the latest and fastest USB standard. Aside from doubling the data signaling rates compared to it’s predecessor,USB4 brought forth numerous improvements, which deserve an article of their own.
As modern devices are already adopting USB4, the implementation of USB 3.2 has been quite limited. Recently, the EU proposed mandatory USB-C, which further impacts the usage of USB 3.0 and USB 3.1 as well.
While this doesn’t bode well for USB 3, it’s likely a good thing for USB in general, and users as well. Even though USB4 products are slightly more expensive, the numerous improvements make it well worth it. And the prospect of a universal connector type is always welcome as well.
