The difference between cheap SSD and expensive SSD 1. Brand difference of SSD Why is the price difference of SSD so big? I believe the first thing that comes to mind is the brand difference of SSD. Brand does affect the pricing of a product. The price of a good brand is indeed more expensive, but it makes sense that a good brand is more expensive, mainly because the products are better in materials, better in quality control, lower in repair rate and more perfect after-sales. However, the solid-state quality control of three-line and unknown brands may be poor, and the selection of main control and particles may be poor. There may be a master of miscellaneous brands, bad particles of black film and white film, and even marking particles after renovation and polishing. The quality can't be guaranteed, and repair rate is higher. In short, first-class prices are first-class goods.
But in fact, in addition to brand differences, even the same brand, the same capacity, there are many differences in price, mainly in terms of reading and writing performance, granularity, master control, interface and so on. Second, flash memory particles are different. When we buy SSDs, we may find SSDs with the same brand, capacity and interface. However, the prices of SSDs are quite different, and there may be different flash particles. For example, Samsung 860EVO and Samsung 860QVO, two solid state drives with SATA interfaces, may only find different colors if we don't understand them deeply, but in fact the particles are different. Samsung 860EVO uses TLC particles. At present, Samsung 860QVO uses QLC particles, which is also 1TB. Because of the particles, the difference between them is almost the same as that of 400 yuan. Including intel760P and 660PM.2, because the particles are different.
So why do different particles lead to different prices? What is the difference? The particles mainly include QLC, SLC, TLC, TLC and so on. SLC is used for enterprise servers, and MLC has gradually withdrawn from the market. At present, the mainstream in the market is thin-layer particles, and QLC particles are newly introduced. The differences between them are as follows. The full name of SLC is monolayer cell, which has monolayer electronic structure. Each cell can store 1 bit data, and the SLC reaches 1 bit/cell. When writing data, the voltage variation range is small, the P/E life is long, and the theoretical erasing times are more than 65,438+million times. However, due to the highest cost, SLC particles are mostly used in enterprise-level high-end products. The full name of MLC is Multi-LevelCell, which adopts double-layer electronic structure with different high and low voltages. The MLC reaches 2bit/cell, and the P/E life is long. Theoretically, the number of erasures is about 3,000-5,000, and the cost is relatively high. But it is also acceptable for the consumer level, and it is mostly used for high-end products at home. The full name of TLC is Trinary-LevelCell, a three-layer storage unit, which is an extension of MLC flash memory. TLC reached 3bit/cell. Because of the high storage density, the theoretical capacity is 1.5 times that of MLC, and the cost is lower. However, the lifetime of P/E is relatively short, and the theoretical erasing times are between 1000-3000 times. It is the mainstream flash memory particle in the market at present. The full name of QLC is Quad-LevelCell, which is a four-layer storage unit. QLC flash particles have higher storage density and lower cost than TLC. The advantage is that the capacity can be made larger and the cost is lower. The disadvantage is that the life of P/E is short, and the theoretical erasure times are only 150. Which is better, TLC or QLC solid particles? Through the above introduction, we find that the biggest advantage of QLC lies in its lower cost. At the same cost, it can make solid-state hard disks with larger capacity, and the capacity is no longer limited. The capacity of 1TB is basically nothing for QLC particles, and tens to hundreds of TB are the mainstream, so the solid QLC particles we see are basically above 5 12GB, like120 G. Although QLC particles reduce the cost and make solid-state hard disk enter the era of large capacity quickly, the shortcomings of QLC particles lead to poor reputation of users. The more data stored per unit cell of QLC particles, the higher the capacity per unit area, and the more different voltage states, the more difficult it is to control. Therefore, the particles containing QLC have poor solid-state stability, low P/E lifetime and the slowest speed among these particles. Therefore, QLC particles are undoubtedly inferior to TCL particles in stability, longevity and reading and writing speed. In contrast, TCL flash memory particles are undoubtedly better. But in fact, MLC particles have a better reputation than TCL particles in the past, but the cost is higher. In order to consider the cost factor, manufacturers gradually eliminated them, so the MLC solid-state products on the market basically disappeared at present. However, with the development of technology, TLC granular solid-state drives are not what they used to be, and both performance and durability have been greatly improved. Third, the interface is different and the protocol is different. At present, the most mainstream interfaces of SSDs on the market are SATA3.0 and M.2, and the interfaces of SSDs with SATA3.0 interface are the same as those of mechanical hard disks. We know that the maximum transmission speed of SATA3.0 channel is 6Gbps, and the actual speed is 560MB/s, which also means that the development of SSD with SATA3.0 interface in the market has encountered a performance bottleneck! Therefore, with the solid state of the M.2NVME protocol and the PEI-E channel, the bandwidth is larger and the performance is naturally improved by leaps and bounds.
M.2 SSD looking for NVMe protocol! In addition, not all M.2 interfaces are based on NVMe protocol and PEI-E channel, so when we choose M.2 interface SSD, we must pay attention to whether it supports NVMe protocol or SATA protocol. If it is the M.2 SSD of SATA protocol, there is little difference in speed with the ordinary SATA SSD, only the interface difference, while the NVMe protocol takes the PCI-E channel, while the current mainstream PCI-E3.0 can provide nearly 32GB/s bidirectional bandwidth, while the bandwidth of 3.0 specification is doubled compared with PCI-E4.0.. Because the PCI-E channel has enough bandwidth, it can greatly increase the space and make the transmission speed faster.
Even M.2NVMe has a speed difference! Maybe if we buy an M.2NVMe protocol SSD with the same brand and capacity, or even an M.2NVMe solid state, we will find that the labeling speed is different and the natural price is different. The sequential reading speed of M.2 SSD of the relatively entry-level NVMe protocol is about 1500MB/s, and its performance is relatively good, even exceeding 3000MB/s, which is the main control and flash memory granule. In this paper, not all hosts need to access M.2NVMe SSD, which is totally unnecessary for relatively entry-level hosts. For example, SSD with SATA interface is completely sufficient for ordinary office and low-demand home. You might want to visit it. The entry motherboard may not support the M.2 slot. For those who are productive, play games and have high performance requirements, it is recommended to access the M.2NVMe SSD. Generally, the mainstream or above level is equipped with M.2NVMe SSD. The above is the difference between cheap SSD and expensive SSD shared by computer city Fengge. Of course, there are many reasons why the price difference of SSDs with the same capacity is so great. For example, different channels have price differences, such as brand premium, good or bad materials, and even different agreements. It is impossible to sell them for no reason, but the truth is that the price is first-class and the goods are first-class. The water in the computer is deep, not only the solid-state hard disk, but also any hardware in the computer has these problems.