Solid-state hard disk (SSD), also known as solid-state hard disk, is a hard disk made of solid-state electronic memory chip array.
Solid state disk, named after Taiwan Province Province, is called solid capacitor in English. SSD consists of control unit and storage unit (FLASH chip, DRAM chip).
Solid-state hard disks are completely the same as ordinary hard disks in interface specifications and definitions, functions and usage methods, and basically the same in product appearance and size (the emerging solid-state hard disks in U.2 and M.2 forms are completely different from SATA mechanical hard disks in size and shape).
Widely used in military, vehicle, industrial control, video monitoring, network monitoring, network terminals, electric power, medical care, aviation, navigation equipment and many other fields.
The working temperature range of the chip is very wide, from 0~70℃ for commercial products to -40~85℃ for industrial products. Although the cost is high, it is spreading to DIY market.
Because the technology of solid-state hard disk is different from traditional hard disk, there are many emerging memory manufacturers. Manufacturers only need to buy NAND particles, match the appropriate control chip, and write the main controller code, so they can manufacture solid-state hard disks.
SATA-2 interface, SATA-3 interface, SAS interface, MSATA interface, PCI-E interface, M.2 interface, CFast interface, SFF-8639 interface and NVME/AHCI protocol are widely used in the new generation of solid state drives. [ 1]
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Classification method:
There are two kinds of storage media for solid-state hard disks. One is to use FLASH chips as storage media, and the other is to use DRAM as storage media. The latest is Intel's XPoint particle technology.
Solid state drive based on flash memory;
IDEFLASH DISK (serial ATA flash disk): Flash chips are used as storage media, which is also commonly known as SSD. Its appearance can be made into various shapes, such as notebook hard disk, micro hard disk, memory card, U disk and so on. The biggest advantage of this SSD is that it can be moved, data protection is not controlled by power supply, it can adapt to various environments and is suitable for individual users. Long service life, depending on different flash media. SLC flash memory generally reaches tens of thousands of times that of PE, MLC can reach more than 3000 times, TLC can also reach 1000 times, and the latest QLC can also guarantee a life of 300 times. The average user writes less than 50 times the total capacity of the hard disk in one year, and even the cheapest QLC flash memory can provide a writing life of 6 years. The reliability is very high, and the failure rate of high-quality domestic solid-state hard disks can easily reach one tenth of that of ordinary domestic mechanical hard disks.
Based on DRAM category:
Solid-state hard disk based on DRAM: As a storage medium, DRAM has a narrow application range. It imitates the design of traditional hard disk, can be set and managed by file system tools of most operating systems, and provides industrial standard PCI and FC interfaces for connecting hosts or servers. The application mode can be divided into SSD hard disk and SSD hard disk array. It is a high-performance memory, which can be written infinitely in theory, but the fly in the ointment is that an independent power supply is needed to ensure data security. DramsSSD is a relatively non-mainstream device. [ 1]
Based on 3D XPoint class
Solid-state hard disk based on 3D XPoint: It is close to DRAM in principle, but it belongs to non-volatile storage. The read delay is extremely low, which can easily reach 1% of the existing solid-state hard disk, and has an almost infinite storage life. The disadvantage is that the density is relatively low compared with NAND, and the cost is extremely high, which is mostly used for fever-level desktops and data centers.
Development history
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1956, IBM invented the world's first hard disk.
1968, IBM once again put forward the feasibility of "Winchester" technology, which laid the development direction of hard disk.
1970, Sun StorageTek developed the first solid-state hard disk drive.
1984, Toshiba invented flash memory.
1989, the world's first solid-state hard disk appeared.
In March 2006, Samsung took the lead in releasing a 32GB solid-state hard disk notebook computer.
In June, 2007, SanDisk Company released 1.8-inch 32GB solid-state hard disk products, and in March released 2.5-inch 32GB models.
In June 2007, Toshiba introduced the first 120GB solid-state hard disk notebook computer.
In September, 2008, Yizheng MemoRight SSD was officially released, marking the acceleration of China enterprises to enter the solid-state hard disk industry.
With the development of SSD in 2009, major manufacturers flocked in, and storage virtualization officially entered a new stage.
20 10 February, Magnesium released the world's first solid-state hard disk with SATA 6Gbps interface, which broke through the reading and writing speed of 300MB/s with SATAII interface.
At the end of 20 10, Rennes Renice launched the world's first high-performance mSATA solid state drive and obtained a patent. [ 1]
In 20 13, Samsung introduced VNand 3D flash memory.