Recently, many friends have asked me about the USB interface, and many of them have very serious misunderstandings.For example: think that USB3.2 must be better than USB 3.1, and USB 3.1 must be better than USB 3.0, or USB Type-C interface must be faster than USB Type-A interface.Speaking of it, USB cables and interfaces are almost the most common things we encounter every day, but there are still many friends who do not understand its basic concepts. Today I will try to clarify this matter for you in the shortest possible time.
The first thing to understand is the USB protocol standard: Many friends know that USB has standards such as 2.0, 3.0 , and 3.1 .
The organization that developed this standard is called USB-IF . It has been scolded miserably in the past two years because it confuses the USB standard too much.
For example, for Wi-Fi, the naming convention has been simplified from the anti-human 802.11n, 802.11ac, and 802.11ax to Wi-Fi 4, Wi-Fi 5, and Wi-Fi 6. It is easy to understand and everyone is happy.
The standard naming of USB is more and more confusing. In 2000, the USB 2.0 standard was born. In 2008, USB 3.0 was officially released. The transmission rate of the interface was greatly increased from 480Mbps to 5Gbps, which is a qualitative leap.
So most friends know that copying files with USB 2.0 is a very painful thing. The actual speed is generally only about 30M per second, while the actual speed of USB 3.0 can easily exceed 100M.
In 2013, USB 3.1 was released, and the interface rate doubled on the basis of USB 3.0, reaching 10Gbps .
At this time, the USB-IF organization started to do things. It renames the USB standard. Rename USB 3.0 to USB 3.1 Gen 1 (the first generation of USB 3.1), and the newly released USB 3.1 standard is renamed to USB 3.1 Gen 2 (the second generation of USB 3.1).
In other words, in the new standard naming, there is no longer the name USB 3.0. This caused the first wave of chaos to erupt. For example, a certain treasure seller will tell you that mine is a USB 3.1 interface, which must be faster than the USB 3.0 next door! Of course it is more expensive!At this time, if we pay the bill because of this, it is an IQ tax.
Now we know that USB 3.0 and USB 3.1 Gen 1 are exactly the same, but with a different name. At present, most of the ports on the market that claim to be USB 3.1 are actually the past USB 3.0.The really faster USB 3.1 Gen 2 is also available. How to distinguish?
The easiest way is to look at the color: the USB socket is black or white, it is USB 2.0, and the speed is the slowest .If it is blue, it is USB 3.0 or USB 3.1 Gen 1 , which is the most common at present. And the fastest USB 3.1 Gen 2, the general interface is red.
When we finally feel that we have memorized the USB naming convention. In 2017, the USB 3.2 standard was born, and the maximum rate was increased to 20Gbps, double that of USB 3.1 Gen 2.
Then, USB-IF came to another show operation. According to the latest naming convention, USB 3.0 and USB 3.1 have completely disappeared in the long river of history, and they have all been included in the sequence of USB 3.2.
Therefore, USB 3.0 and USB 3.1 Gen 1 with an interface rate of 5Gbps were renamed as USB 3.2 Gen 1 ;The USB 3.1 Gen 2 with an interface rate of 10Gbps was renamed as USB 3.2 Gen 2;The latest release of the fastest 20Gbps interface rate USB 3.2 is called USB 3.2 Gen 2x2 .
Are you dizzy already?
If you are not dizzy, and you can still stay awake, then you will know that we see USB 3.0, USB 3.1, and USB 3.2 in the market now, and they are most likely to be the same thing at all. So don't be fooled.With such frequent name changes, the most worrying thing is not the consumers, but the manufacturers. With a swipe of your USB-IF pen, the name is changed. I have stamps here! How can I change it?
Therefore, on the latest computer motherboards, USB xx is generally not written on the USB interface, which is too messy. Simply switch to market naming. They are SuperSpeed (SS), SS 5Gbps and SS 10Gbps respectively .That makes it pretty clear, SS is the slowest USB 2.0, SS 5G stands for Gen 1, and 10G stands for Gen 2. As for the 20Gbps Gen 2x2, we may not see it in a short time.
In order to communicate conveniently and accurately in the future, we can also use USB 2.0, USB 5G, and USB 10G to communicate as much as possible, so that there will be no misunderstanding.
Generally speaking, it is the most intuitive to judge by color.Black and white USBs are the slowest, and they can be used to connect devices such as mice and keyboards that do not require transmission speed.
The blue USB is faster, and you can use them to connect a U disk or a mobile hard disk.
The red USB has the fastest speed, and using them to connect to an external SSD solid state drive can exert the greatest effect.
Then the problem comes again: unlike the USB Type-A interface, we can’t see the color of the USB Type-C interface, so how do we distinguish its speed?
The answer is that, apart from the rate value given by the merchant and our actual test, there is really no way to quickly distinguish.What we need to know here is that USB Type-C refers to an interface shape, which is different from the standard speed we just mentioned.
The USB Type-C interface can be 10G standard or USB 2.0 standard, so it really cannot be said that Type-C is definitely faster than Type-A. It just provides a more compact interface form, and a more convenient connection method that can be plugged in both front and back.
inally, I need to remind you that if you want to achieve the fastest transmission efficiency between two devices, then device A, cable, and device B must meet the USB 10G standard at the same time , otherwise you can only follow the short board transmission rate.
n addition, it needs to be reminded that the current high-speed transmission line that meets the USB 10G standard , whether it is Type-C or Type-A, generally has a length of no more than 1 meter . If the length exceeds this length, the fastest transmission rate cannot be guaranteed.Just like Apple's 40Gbps Thunderbolt 3 data cable, in order to ensure the speed, the longest will not exceed 0.5 meters.
If the wire is four or five meters long, and the merchant guarantees a good speed, so it is more expensive than the next door, then...you know what to do now.
