Every year, there are cases of lithium battery explosion, but because of Samsung Note7, we have added a lot of battery related knowledge. Recently, the "flash gate" of a domestic manufacturer has also led to a wave of popular science about "flash memory type and file system". However, many readers may be confused when they see such terms as UFS 2.0/2.1 and eMMC, F2FS and EXT4. Take this opportunity to bring you some simple science popularization.
When it comes to mobile phone performance, the first thing you think about is CPU and GPU performance, But flash memory is also a component that directly affects the speed of application startup and game loading. The former is mainly affected by random read/write performance, while the latter is mainly affected by continuous read/write performance. In 2017 One of the factors that have the greatest impact on random and sequential read/write performance is this The protagonist of popular science—— File system and flash type. This flash gate is mainly aimed at flash memory types such as UFS and eMMC.
How to view flash memory type
SSDs used by current computers, eMMC on Android phones UFS， Flash flash technology is adopted, and their main differences lie in the controller, interface and flash memory specifications. From eMMC to UFS, it is mainly a multiple speed increase, while the focus of the improvement from UFS 2.0 to UFS 2.1 is not speed More advanced function support such as equipment health status description and preventive maintenance has been added. Only Toshiba's THGA series UFS 2.1 products have improved the random read and write performance.
The specific historical reasons and technical differences of these kinds of flash memory, as well as the content of MLC, TLC particles and so on, will not be expanded here until the next opportunity. But it should be noted here that, Advanced circuit design is required to make the machine compatible at the same time UFS and eMMC are far from simply replacing flash memory chips. This flash memory door, it is likely that the machine is at the beginning of the product design, and has made preparations for the later replacement of flash memory.
in the light of This flash memory disturbance mainly focuses on the flash memory specifications mentioned above. The earliest question also came from“ yes eMMC， UFS or UFS ", and slowly extend to" UFS 2.0 or UFS 2.1 ". Love to play computer games stay here Three identification methods are summarized:
Test the read/write speed of the machine through AndroBench and other flash speed testing software, and determine the indirect flash size. The highest speed below 300MB/s is likely to be eMMC, near 500MB/s it may be UFS 2.0, and above 700MB/s it may be UFS 2.1.
Image source @ magician Dan Xiaoding
Enter ls/proc/fs/* in the terminal simulator (the same type of software can also be used), as shown in the figure above. Under the/proc/fs/f2fs information, if sd is the prefix, its flash memory is UFS. If mmcblk is the beginning, it is eMMC.
Screenshot of Xiaomi 6
If you want to To check the type of flash memory, the most direct way is to disassemble the machine and look at the model of the chip directly. The fastest way to avoid disassembly is to use a terminal simulator (the same type of application can also be used), enter cat/proc/scsi/scsi, and the Vendor will have the flash memory model marked (as shown in the figure above). This method does not require root permission, but it is not guaranteed that the manufacturer will deliberately block or even cheat in the future, so it is recommended to check early screenshots.
You can check the flash memory used by your Huawei/Glory series models by comparing the table summarized by netizens:
Overview of Toshiba and Samsung UFS2.0/2.1 flash memory models
The V9 we have (screenshot is in the second part below) uses Samsung KLUDG8J1EB-B0B1. This flash memory model has not been entered into the official website of Samsung Electronics at the time of the deadline. However, Ainongji learned from Samsung insiders that the KLUCG4J1EB-B0B1 of the same series is a 64G UFS 2.1, and this KLUCG8J1EB-B0B1 does not necessarily mean UFS 2.1.
Toshiba eMMC Product Model Table
Samsung eMMC Product Model Table
UFS and eMMC, Influence of flash memory type on sequential read/write speed
Query Results of 6 Flagships
256G version of Xiaomi MIX, UFS 2.0 flash memory (dual channel), using the EXT4 file system
64G Huawei P10, UFS 2.0 flash memory (dual channel), F2FS file system
128G version of One Plus 3T, UFS 2.0 flash memory (single channel), F2FS file system
F2FS and EXT4, the impact of file systems on random reads and writes
"File system" is a method of storing and organizing data, which can be generally understood as the "format" of file storage. FAT16/32 NTFS， There are many file system types on Linux platform, including EXT2, EXT3, EXT4, NFS, and SMB. Now the file system commonly used by the Android camp is EXT4, which is moving towards F2FS.
F2FS (Flash Friendly File System, literally translated as flash friendly file system) was originally designed by Samsung Electronics for the use of Linux kernel systems. Its specific improvement is to optimize the index speed, improve the transfer speed of small files, and significantly improve the random reading and writing performance. But now there are slightly larger space occupation and slight compatibility problems.
With the change of engineers in this technology from Samsung to Motorola, and finally to Huawei, this technology has also been widely used on Moto and Huawei/Glory models. The F2FS file system has been used on Moto X as early as 2013 (Moto in that year is really forward-looking). But what's more special is that the official system of Samsung mobile phone still uses the traditional EXT4 file system, while the official system of One Plus 3T already uses F2FS.
Third party developers are much more enthusiastic than manufacturers. In 2014, XDA players used the F2FS file system on the third-party kernel of Sony Xperia Z1, and systems above CM13 and many third-party ROMs have already used F2FS.
As a software technology, the most impressive thing about F2FS is that it can be used not only on UFS, but also on eMMC with weak performance and "expired" performance, greatly improving the random read and write performance, and old models can also benefit from it. Users of old models who want to experience the new file system can manually convert it through TWRP recovery. You can view the file system used by the mobile phone through the mount command in the terminal simulator.
Results summary
Among the six models, the latest Samsung S8+and Xiaomi 6 are confirmed to use UFS 2.1 flash memory. The "oldest" One Plus 3T is the only HS-G3 single channel flash memory product. However, note that Huawei P10, Glory V9, and One Plus 3T all use the F2FS file system (according to Samsung insiders, the KLUGG4J1EB-B0B1 of the same series is the 64G UFS 2.1, and the KLUGG8J1EB-B0B1 is probably the UFS 2.1).
Although the F2FS file system will have a certain bonus, in the sequential read/write test, In particular, the continuous write performance is still directly related to the flash memory type and capacity. In random reading, especially random writing, the improvement brought by F2FS is overwhelming (It can be used as a joke: most people's efforts are so low that they don't need to compete with their innate talents) 。 Among them, although the flash memory capacity of Glory V9 and One Plus 3T is the same The former has doubled its performance. The main reason here is probably flash memory Congenital difference between single and double channels.
It is inevitable that there will be omissions when one person writes a paper. We also hope that you can communicate and correct, Running points library Links can be stamped here . I hope that the world will never hit the patriot of eMMC again.
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