Witness the mobile phone memory card from glory to disappearance

Part 1

     Today, I found a old mobile phone that I haven't used for many years. I took off the back cover, and it contained this mobile phone memory card that everyone must have a long time ago, but now it has disappeared from our field of vision. To be precise, it is called a TF card. Did seeing this little card bring back a little memory for you? In the era of full-screen smart phones, how can the TF card of the mobile phone gradually disappear when it is used?

    TF card full name: Trans FLash, launched in 2004. It is an ultra-small card (11*15*1MM), which is about 1/4 of the SD card, and is the smallest memory card at present. In the early days, only Motorola's mobile phones used TF cards. Later, SanDisk merged TF cards into SD Association and became one of the products of the SD family, so it was called micro SD card. This created the most widely used mobile phone memory card later, micro SD card has a universal protocol and can be purchased and used anywhere in the world. The shape is small and light, the capacity is large, and its compatibility is very strong, which can solve the problem of large file storage and transmission of mobile devices such as mobile phones and computers. Then the price of ordinary memory cards is also very cheap now, and there is no need to spend more than 40 yuan to buy a 2G card like when I was in school, but when it comes to the decline of micro SD cards. It can probably be boiled down to three points, speed, design and commercial interests, so let's talk about speed first.

     First of all, we can start with the speed. The read and write speed of the card was slower than the built-in storage of the mobile phone, but the built-in storage of the mobile phone was too small at that time. Consumers need to spend hundreds or even thousands more to change from 8GB to 16GB, or 16GB to 32GB, which was unacceptable to many consumers at that time, so everyone generally buys a memory card to expand the capacity. Consumers do not have a very clear concept of reading and writing speed, but the amount of space left on the mobile phone is visible to the naked eye. When I bought mobile phone accessories, I found that a memory card cost more than 100 yuan. In view of the rampant use of fake cards and expansion cards on the market, their performance faulty caused the phone to freeze. In the early days of Android, applications could be installed directly on the card. Consumers who did not know the truth would not realize that this was a problem with the card. They would think that it must be system garbage. Before Android 4.0, I myself tended to install apps on an external storage card, because the built-in storage of my phone was always reluctant to use. Another important point is that the TF card is not a permanent connection design. Even on some devices, the SD card is not working for a long time, and even sleeps or when the mobile phone is connected to the USB mode of the computer, some TF cards will be uninstalled. Or pop-up, and such unstable mounting may cause the data file of the application to be damaged, so after the Android system version 4.4, the user can only install the application on the mobile phone's own storage. Later, with the development of the times, the reading and writing speed of the built-in storage of mobile phones has broken through the sky. Although the reading speed of TF card has improved, it has not experienced a revolutionary growth. Today's mobile phones with UFS3.1 flash memory function can read and write at speeds close to 1800MB/s, while the fastest TF cards can only reach to 100MB/s.