Seeing the price, the first reaction in my mind is, who will buy this nearly 1000 yuan data line? Is poverty limiting my imagination, or is apple crazy about money? < / P > < p > let’s take a look at the appearance of this data line. In fact, it is a data line with a black braided design and a length of 2m, with both ends of type-c. the reason why Apple named its data line “Thunderbolt” is mainly because it supports the “Thunderbolt” transmission technology protocol, which is translated as Thunderbolt, commonly known as thunder and lightning. < / P > < p > Apple thunderbolt 3 Pro data line’s sharp thinking partners may find the key point at a glance, that is, black woven material, “this is why Apple is expensive”, but if you go to Jingdong tmall and other e-commerce platforms, you will find that there are dozens of yuan worth of black woven material data lines. < p > < p > according to Apple’s official data, the data transmission rate of thunderbolt 3 Pro is up to 40Gbps, and that of USB 3.1 is up to 10Gbps. It supports DP video output, can be connected to devices and displays supporting thunderbolt 3 or usb-c, and the power supply can be up to 100W. < / P > < p > Apple tells you that you can use this cable to connect Macs equipped with thunderbolt 3 ports to thunderbolt 3 devices, such as pro display XDR, pedestal, and hard disk. < / P > < p > from the data point of view, the highest transmission data of thunderbolt 3 Pro is the top level at present. What are the technologies behind these top-level data transmission? Next, I will give you a brief introduction to science popularization. The main terms are type-C, USB 3.1, and lightning 3. < / P > < p > first of all, type-C is just an interface standard, or interface form, which is different from the previous micro USB interface, which uses USB 2.0 transmission protocol. USB 3.1 is the latest transmission protocol, initiated by Intel and other companies. Its maximum data transmission can reach 10Gbps, which is one of the peak transmission speed of Apple’s thunderbolt 3 Pro. < p > < p > lightning interface is another transmission protocol, which is also initiated by Intel. It integrates pciexport data transmission technology and DisplayPort display technology, which can transmit data and video signals at the same time, and each channel provides bidirectional 10Gbps bandwidth. The latest lightning 3 can reach 40Gbps, which is completely consistent with Apple’s publicity data. What is the concept of transmission speed? Simply put, it takes less than a minute to copy 14 hours of high-definition video and 25000 photos. Therefore, for ordinary users, the transmission of any data is instantaneous. < / P > < p > at the same time, thunderbolt 3 and the full-featured type-C with USB 3.1 can quickly charge mobile phones, tablets, laptops and other devices, and their maximum power supply capacity can reach 100W. This is the fundamental reason why Apple thunderbolt 3 Pro supports up to 100W fast charging. At present, many common type-C cables on the market do not support fast charging. < / P > < p > however, having top-level data transmission is only one of the reasons why the price of Leili 3 Pro is expensive. Another key reason is the technical difficulty caused by the length of the line. The signal transmission lines on the market can be divided into two types: coaxial line and twisted pair. The coaxial line is composed of a layer of insulating layer wrapped with a central copper conductor and a metal mesh layer wrapped outside the insulation layer. Since the outer metal network and the central axis are on the same axis center, they are called coaxial lines. The data lines supporting the lightning transmission protocol are composed of multiple groups It is composed of coaxial line and independent power transmission line. However, the attenuation of signal transmission in the coaxial line is related to the transmission distance and the frequency of the signal itself. For high-frequency signals, the further the transmission distance is, the greater the signal attenuation is. In order to realize long-distance transmission of high-frequency signals, coaxial amplifiers are used in industry to amplify and compensate signals. Generally speaking, lightning 3 data line with length less than 0.5m needs passive chip, while lightning 3 with length over 0.5m needs active chip. However, the price of active chip is several times higher than that of passive chip. Therefore, in order to save costs, the lightning 3 data line on the market before was generally not more than 0.5m. However, two years ago, apple extended the lightning 3 data line to 0.8m, which was called “limit”. Now the technical difficulty and price of 2m cable can be imagined. < / P > < p > if you open the e-commerce platforms such as Jingdong tmall to search for “2m lightning 3”, you will find that the 2m long lightning 3 data cable on the market is also very expensive, with prices ranging from 300 yuan to 700 yuan. So, if you add in Apple’s brand premium, Apple’s thunderbolt 3 Pro isn’t really expensive. However, the line is one thing, whether the device supports it or not and whether the user needs it is another matter. Although this is specially prepared for Apple users, it seems that most Apple users are not “appreciative”. An apple nearby said faithfully, “it’s a waste to buy such a luxurious data line and not use it.” < / P > < p > after a small-scale research, I found that the data transmission of many iPhone, macbook and IMAC users around is very traditional. Either icloud or special ordinary data transmission cable is used. The use of this cable I can imagine is an external video card. Even if connected to a 4K or higher resolution display, this cable is very luxurious. < / P > < p > in addition, apple officials also said that Apple thunderbolt 3 Pro can connect up to six thunderbolt 3 devices through daisy chain. Huawei has finally made a choice! Xiaomi and ov have also followed up. Have you ever thought about today?