# Advanced Data Mining of SSD Quality Based on FP-Growth Data Analysis
## 2 Literature Review
### Ssd  
The SSD, also called the electronic hard disk, uses semiconductor technology to store data in NAND flash memory. This is different from the HDD, which works with many mechanical structures to save data by using magnetic technology. Technically, the SSD is more suitable for notebook computers or various portable electronic products, as it allows them to take advantage of the low power consumption, small size, fall resistance, and shock resistance. The main components of the SSD are as follows:  
* SSD controller:  
As the main core of the SSD, the SSD controller plays a role in maintaining the functional operation and adjustment of all chips on the SSD and acts as the communication bridge between the SSD and computer. Different SSD controllers [16] have different computing capabilities; the mainstream chips at present are Marvell, Silicon Motion, Phison, and JMicron.  
* NAND Flash Memory:NAND flash memory [17], the heart of the SSD, can retain stored data and information in the event of power failure, since it is a kind of nonvolatile memory. The HDD works with the magnetic principle to store data on the disk, while the SSD uses the current to store electrons in NAND flash memory to save data.
* Types of NAND flash memory:  
NAND flash memory can be divided into four types according to the electronic structure: SLC [18], 1 bit/cell; MLC [19], 2 bit/cell; TLC [20], 3 bit/cell; QLC [21], 4 bit/cell. The sequence is SLC > MLC > TLC > QLC in terms of storage speed and SLC > MLC > TLC > QLC in terms of cost. At present, the mainstream SSD in the consumer market is the TLC chip, and the QLC chip has also been launched, which can provide more capacity and accelerate the replacement of the HDD.
* Advantage and disadvantage of the SSD:  
Advantage: The SSD has the advantages of good shock resistance, low power consumption, low noise, and low heat, thereby allowing the data to be stored in it more safely, and the read-write performance is better than that of the HDD. Disadvantage: The disadvantages of the SSD are its high cost and limited PE cycle; that is, the speed of the SSD gradually slows down with the increase in PE cycle, and it cannot be recovered after being damaged. The data stored inside are almost lost when failure occurs. The bottleneck of the current SSD is represented by the NAND flash memory and SSD controller technology.  
[PERSON] et al. [22] explain that the input-output (I/O) bus on the host terminal of the computer system is limited; thus, the real read-write speed of the SSD cannot be obtained. Therefore, in-storage processing is proposed, and a method of operating the host CPU directly in flash memory of the SSD is designed to improve and accelerate the read-write capability of the main database to full efficiency. [PERSON] [23] analyzed more than 130 million units of hard disk failures in the data center during actual operation and made the following observations: (1) the increase in the hard disk environment temperature is more likely to cause breakdown of the hard disk; (2) the main faults are caused by shaking; (3) the failure rate observed on the field side of the hard disk is higher than that provided by the spec at actual delivery. The SSD has gradually become the mainstream storage device, and most of the related papers discuss how SSD quality can be improved and how read-write performance can be enhanced. In this study, data mining is used to solve the problem and propose strategies to improve the quality management of the SSD by computer manufacturers.