More than a decade ago, the USB bus entered the mainstream field of vision, providing a new direction for storage, and using a unified standard to pull many peripherals into its own camp. This is a huge contribution they have made to the entire industry, and no one will deny it. However, organizations promoting USB have unique naming techniques that are difficult to understand: more than a decade later, three major versions of the USB standard have evolved, not only creating a bunch of aliases, but the emergence of USB 3.1 also distinguishes between Gen1 and Gen2, let alone the interface forms defined by Mini USB, Micro USB, and Type-ABC.

This makes us ordinary people feel a headache. In the past, we used to judge which one was faster based on the color of the interface and plug at a glance. Now, looking at these newly emerging things, we can't distinguish them clearly. If we want to choose a mobile SSD, we don't know how to choose among so many interfaces. Below, the author will help us popularize the differences between USB interfaces.

Looking back at the USB standard from 1.0 20 years ago to 3.0, which is widely accepted today, the USB standard has gone through four iterations: 1.0, 1.1, 2.0 and 3.0. If you just look at Arabic numerals, people who pass primary school mathematics can know which version is more advanced. But USB-IF has a hobby of creating stage names, and they have also given names to transmission rates: 1.5Mbit/s is called Low Speed, 12Mbit/s is called Full Speed, 480Mbit/s is called Hi Speed, and 5Gbit/s is SuperSpeed. The impact of language is much greater than cold numbers.

Unfortunately, the transfer rate is bound to be linked to the USB standard version, so USB-IF feels that naming several USB versions directly with the transfer rate may also be quite appealing, such as Hi Speed USB and SuperSpeed USB. As a result, the problem arises. When there are multiple names for a thing, once mixed up, it becomes confusing. Everyone looks very fast, how can I know which one is USB 3.0.

In addition, USB also has a great feature called Backward compatibility, so USB-IF simply lets the new standard "eat up" the old standard, and then divides the old transmission rate under the new standard, so in rare cases you can see such wonderful things as Full Speed USB2.0.

This mess should have been an uncontrollable situation, but fortunately, USB-IF came up with a surprise move to promote USB 3.0- changing the color of the interface. They decided to use blue as the color scheme for the interface plastic board of USB 3.0/SuperSpeed USB standard devices to distinguish them from the old standard interfaces. The crowd was filled with joy at once, and even those who were nearsighted could immediately recognize which interface standard was updated faster. Although downstream hardware manufacturers feel a pain when they see 5 more pins added to the connectors, they have gritted their teeth and introduced new interfaces. Compared to the increase in cost, the promotion effect is still worth it.

In July 2013, the USB organization released the USB 3.1 standard. According to the usual logic, USB 3.1 is an upgrade to USB 3.0, but discussing whether USB 3.1 is faster than USB 3.0 or what other advancements exist today is an unfounded topic, as USB 3.0 no longer exists in the definition of USB-IF. Among the remaining current standards, except for Hi Speed USB, which represents the 2.0 standard, there are only SuperSpeed USB and SuperSpeed USB10Gbps.

USB 3.1 Gen 1 is the original USB 3.0, and the true new standard is called USB 3.1 Gen 2.

From a purely paper-based perspective, the USB 3.1 Gen 2 standard has doubled the theoretical transmission rate to catch up with the first generation Thunderbolt. While increasing the encoding bit width from ten bits to hundreds, it has also reduced the signaling overhead from the original 20% to 3%, which is a significant improvement.

For example, the Samsung Mobile SSD T5, which adopts USB 3.1 Gen 2, can achieve a transmission speed of 540MB/s. However, currently, USB drives that support USB 3.1 interfaces on the market are almost all USB 3.1 Gen 1 products.

Samsung T5 speed display

So now the vast majority of people claim to support the "USB 3.1 type-c" standard, but are unwilling to specify whether it is a Gen 1 or Gen 2 electronic product or a PC accessory. In fact, the essence is still the ability of USB 3.0.

When choosing storage products, we should try to choose USB 3.1 Gen 2 products, such as the mobile SSD T5 mentioned earlier.

The above is the author's summary of why mobile SSDs should choose the USB 3.1 interface to be perfect. I hope everyone likes it.

Source: Zhongguancun Online