Hard drive! ! !

Hard disks are divided into solid-state hard disks, mechanical hard disks and hybrid hard disks. Most users adopt the dual-disk scheme of solid-state hard disk and mechanical hard disk. At present, there is little demand for hybrid hard disks in the market, and solid-state hard disks and mechanical hard disks are mainly installed in the market. Let's briefly introduce the knowledge of these three types of hard disks.

First, the type of hard disk purchase:

1, mechanical hard disk (HDD)

It's a traditional hard disk. Before there was a solid state drive, it was a mechanical hard drive. At present, most installed mechanical hard disks are used as storage auxiliary disks. The structure of mechanical hard disk is mainly composed of one or more disks made of aluminum or glass, magnetic head, rotating shaft, magnetic head controller, control motor, data converter, interface and cache. When the mechanical hard disk works, the magnetic head is suspended on the high-speed rotating disk to read and write data.

Advantages are large capacity, low price and mature technology, and data can be recovered when the hard disk is damaged. Disadvantages are slow speed, high fever and noise, and poor shock resistance and fall resistance compared with solid-state hard disks.

2. Solid State Disk (SSD)

Solid state hard disk is a new type of hard disk after mechanical hard disk, and it is also one of the first choice hard disks installed now. Both of them are used as main disks, which greatly improves the system speed. Solid-state hard disk is mainly an array storage composed of multiple flash memory chips, main control and cache, which belongs to the hard disk made of solid-state electronic storage chip array.

The main advantages are faster reading speed and shorter seek time compared with mechanical hard disk, which can improve the reading and writing speed of systems, software and games. , and it is silent, shock-proof and fall-resistant, with low power consumption, light weight and less heat. The main disadvantages are high price and small capacity. When large storage is needed, it often needs to be used with mechanical hard disk.

3. Hybrid Hard Disk (SSHD)

Hybrid hard disk is equivalent to a combination of mechanical hard disk and solid state hard disk. It uses small flash particles to store common files, and disk is the most important storage medium, while flash only plays a buffering role, saving more common files in flash to reduce seek time, thus improving efficiency.

The advantages and disadvantages of hybrid hard disk are mainly that the reading and writing speed is faster than that of mechanical hard disk, but not as fast as that of solid state hard disk. Like mechanical hard disk, it has obvious fever, noise and vibration.

Second, the brand of hard disk purchase

1, mechanical hard disk: Western Digital (WD), Seagate (ST)

2. SSD: Samsung, Intel, Palm, Toshiba, Jianxing, Sandisk, Kingston, Wigan, WD, Galaxy, Colorful, Taipower, etc.

Generally speaking, Samsung, Intel and Proctor are preferred, but they are expensive, followed by Kingston, Sandisk and Toshiba. The brands with high cost performance can be Yingchi, Weigang, Taipower and Qicai.

Third, the hard disk purchase capacity.

At the same price, the capacity of mechanical hard disk is much larger than that of solid-state hard disk, so in the case of large storage, you must cooperate with mechanical hard disk as storage, unless you are a local tyrant, buy a large-capacity solid-state hard disk directly.

The capacity of solid-state hard disk is usually: 120G, 240G, 320G, 500G, 1T, more than 2T. However, at present, the capacity of 120G and 240G is basically chosen, because the price of large-capacity SSD will definitely make you doubt your life, but I believe that after years of development, large-capacity SSD will become more and more mainstream and cheaper.

The capacity of mechanical hard disk is usually: 1T, 2T, 3T, 4T or above. Generally, mechanical hard disks of 1T and 2T are basically selected, no matter how big they are, they are basically not used unless there is such storage demand.

Fourth, the hard disk purchase interface

Mechanical hard disks are all SATA3 interfaces now, and the common solid-state hard disks are: SATA 3 interface, PCI-E interface and M.2 interface, among which M.2 also has different specifications, mainly including 2242, 2260 and 2280.

At present, SATA3 interface SSD is widely used, and M.2 interface SSD has gradually become the mainstream, while PCI-E interface is generally used for high-end computers, with higher speed experience.

Five, the size of the hard disk to buy

The mechanical hard disks of desktop computers are all 3.5 inches, and the solid-state hard disks with SATA3 interface are 2.5 inches, which are similar to the mechanical hard disks of notebooks, so they can also be used in notebooks. PCI-E interface SSD is only suitable for desktop computers, not notebooks, while M.2 and SATA SSD, desktop computers and notebooks are very common.

However, for today's notebooks and desktop computers, SSD with M.2 interface is compact, which breaks the performance bottleneck brought by SATA interface. Therefore, Bian Xiao of Installer House firmly believes that SSD with M.2 interface is the future trend.

What determines the speed of SSD and mechanical HDD?

Solid-state disk is mainly composed of particles and main control, which determines the performance of a solid-state disk. The better the particle and the master control, the faster the SSD will be.

Traditional classification of SSD particles: SLC, MLC, TLC, SLC particles are stronger than MLC, MLC particles are stronger than TLC. However, SLC particles are basically rare in the market now, mainly because of the high price. At present, the high-end solid state is still dominated by MLC particles, while TLC particles have lower cost, worse performance and life, and are positioned as entry-level solid state drives in the market.

SLC = single-stage Cell, i.e. 1bit/cell, which has high speed, long service life, super expensive price (about 3 times the price of MLC) and service life of about 65438+ million times.

MLC = multilevel Cell, that is, 2bit/cell, with average speed and life, and average price, about 1000-3000 erasure life.

TLC = Trinary-Le