You will often see, especially when buying an external storage device with a USB connection, that it talks about different versions of the standard and even different generations of it. So an external SSD could be USB 3.2 Gen.1 or USB 3.2 Gen.2 for example, which can be a bit confusing. For this reason, we are going to proceed to explain, in theoretical terms, what is the bandwidth of each of them to know whether or not there is a significant difference in performance for us as users.
USB 3.1 vs USB 3.2 external SSD
The difference between USB 3.1 Gen 1 and USB 3.1 Gen 2 is only in their bandwidth, because while Gen 1 supports speeds up to 5 Gbps, Gen 2 doubles that speed to 10 Gbps / s. The USB-IF organization decided to give the USB 3.1 and USB 3.2 connections different names just for marketing reasons, but what they got was a lot of confusion among users, especially because they also changed old names.
Since the arrival of USB 3.2, USB technology has advanced even further and since 2017, when USB 3.2 arrived, four variants started to be used, leaving out the previous versions.
| USB 3.2 generation 1×1 | USB 3.2 generation 1×2 | USB 3.2 generation 2×1 | USB 3.2 generation 2×2 | |
|---|---|---|---|---|
| Transfer speed | 5 Gbit / s | 10 Gbit / s | 10 Gbit / s | 20 Gbit / s |
| Formerly known as | USB 3.1 Gen 1 / USB 3.0 | – | USB 3.1 Gen 2 | – |
| Interface options | USB-A, USB-C, micro USB | USB-C solo | USB-A, USB-C, micro USB | USB-C solo |
Thus, according to this table that we have just shown you, the USB 3.1 connections are no longer called that way, but have become USB 3.2 but with different generation numbers. A USB 3.1 Gen 1 is now a USB 3.2 Gen 1 × 1, while a USB 3.1 Gen 2 is now a USB 3.2 Gen 2 × 1. At the very least, confusing, right?
Thus, the difference in performance is obvious because the new generations double or even quadruple the first. When buying an external SSD with a USB connection, the recommendation is to buy models of the USB 3.1 Gen 1 × 2, as these are the ones with 10 Gbps of bandwidth. The high-end models, which normally already have M.2 SSDs mounted with a PCI-Express interface inside, use USB 3.2 Gen 2 × 2.
USB 4, the generation that brings it all together
Few of us are waiting like the May rain for the arrival of USB 4, the specification that in principle will unify everything and make things stop being as confusing as they are so far. This standard will allow speeds of up to 40 Gbps, will be compatible with Thunderbolt 3 and will only use the USB-C interface. Some of the advantages of USB 4 are as follows:
- Display, data and charge / storage functionality with a single USB-C connector.
- Universal compatibility with all existing USB and Thunderbolt products.
- Standardization of port capacities for a consistent and predictable user experience.
- Increased flexibility to configure bandwidth and manage power and other performance parameters to suit system needs.
Now comes the inevitable question, when will USB 4 arrive? Is it worth the wait until it arrives to buy an external SSD? The USB 4 specification was already released in late 2019, and it typically takes around 18 months for the first compatible products to appear, which means we’ll surely start seeing them in mid-2021. Not much left for this, but it is worth the wait or not, it depends on your speed and needs.
