Hardware system refers to the entities and devices constituting the computer system (i.e. the physical computer that can be touched by hand), such as chassis, motherboard and memory. The hardware system is usually composed of five parts: CPU (including arithmetic unit and controller), memory, input device, output device and interface device. Starting from the main components of the computer, let's briefly talk about the functions and purchase of these hardware.
1. CPU:
CPU is the abbreviation of "central processing unit" in English. CPU is generally composed of logic operation unit, control unit and storage unit. The logic operation and control unit includes some registers, which are used for the temporary storage of data during data processing by the CPU. Main functions of CPU (core component): arithmetic unit and controller. The CPU communicates with other parts of the computer through these pins and transmits data and instructions. At present, the mainstream CPU suppliers include the CPUs of Intel and AMD (for detailed types and models, please check online). In contrast, AMD's CPU has advantages over Intel processors of the same grade in three-dimensional production, game application and video processing, while Intel's CPU has advantages in commercial application, multimedia application and graphic design; In terms of cost performance, AMD's processor is slightly better than Intel's.
When purchasing, we should avoid buying fake CPU, and pay attention to whether the packaging line, watermark word and laser label are formal.
For ordinary users, it is best to choose to launch CPU products for one to six months.
2. a main board:
The mainboard is a rectangular circuit board installed in the chassis with the main circuit system of the computer. The expansion slot on the mainboard is used to plug in various interface cards and expand the functions of the computer, such as graphics card, network card, etc. For ordinary users, when purchasing motherboards, they should give priority to famous brand manufacturers or products with good after-sales service. When purchasing, we should also observe the packaging and plate quality of the main board: first observe whether the packaging is formal and whether there is an anti-static bag, and then carefully observe the main board body. The thickness of the main board body is generally about 3-4mm. On this premise, it is appropriate to choose thick.
Note that the production date of the chip on the motherboard (for example, 9452 is the 52nd week of 1994) should not be too different (preferably not more than 3 months), otherwise the performance of the motherboard will be affected.
3. Memory module:
The memory module is used to store the data or program that the computer is using (i.e. executing). We usually say that dynamic memory (DRAM) refers to that when we write data into DRAM, the data will be lost after a period of time, so we need to set an additional circuit for memory refresh operation. In other words, it is just a temporary memory, and the data will disappear after power failure. At present, the mainstream memory capacity is 1-2g and the working frequency is above 8MHz. The printed circuit board (PCB) of the memory module is preferably 6 layers. In addition, the surface of a good memory module has a strong metal finish, and the parts are welded neatly. When purchasing memory modules, we should also choose large manufacturers and products with good after-sales service.
4. Hard disk:
The hard disk is the data storage center of the computer. Almost all the application programs and document data we use are stored on or read from the hard disk. It includes storage disks and drives. It is characterized by large storage capacity. Hard disk is an indispensable storage device in computer. At present, the capacity of hard disk is generally 250-320g, and the cache is generally 2-16m. When purchasing hard disk, you should pay attention to the type of hard disk interface should match your computer (the mainstream interface in the market is SATA interface). When purchasing, pay attention to distinguish between "licensed goods" and "parallel goods". The way to identify "parallel goods" is: first, check whether the anti-counterfeiting label is formal; Secondly, check whether the numbers on the hard disk and the agent warranty are consistent.
5. Optical drive and recorder:
This kind of hardware can usually be inserted into a CD to store data. Optical drives or recorders have high requirements for stability and cache. Therefore, when purchasing such hardware, priority should be given to the products of large manufacturers (such as Sony, BenQ, Samsung, etc.). When purchasing, you should also pay attention to whether the interface type of hard disk matches your computer.
6. Graphics card:
Graphics card is also called display card, graphics accelerator card, etc. The main function is to speed up the processing of graphic functions. The display card connects the CPU and the display through the system bus and is the control device between the CPU and the display. In fact, it is used to store the data information of the graphics to be processed. At present, the video memory of mainstream graphics cards is more than 512MB, and the interface is generally pci-ex16. Graphics card manufacturers mainly include ASUS, gigabyte, Onda, etc. When purchasing a graphics card, pay attention to the matching of the graphics memory with the host performance (the bit width should be more than 128 bit). And give priority to products produced by large manufacturers or with good after-sales service.
7. network card:
A network card is an input / output device that connects a computer to a network. The main function is to process the data sent from the computer to the network cable, decompose the data into data packets of appropriate size according to the specific network protocol, and then send them to the network (most of them are integrated on the motherboard at present). As the practical environment of different types of network cards may be different, the type of network and transmission medium used by the network card and the bandwidth of network equipment connected to it should be clear when purchasing. High quality network cards are made of tinplate, and the exposed part is white; The exposed part of the network card of the inferior painting gold board is yellow. In addition, the identification of the MAC address (i.e. ID number) of the network card is the best way to understand the advantages and disadvantages of the network card. The MAC address of the network card produced by the regular manufacturer is generally a group of 12 digit hexadecimal numbers (the first six digits are the manufacturer ID, and the last six digits are the unique ID assigned by the manufacturer to the network card). When buying, if you find that the MAC address marked on the network card given by the merchant is the same, it must be a poor product. Finally, it depends on the workmanship of the product. The advantages and disadvantages of workmanship are reflected in the solder joint, golden finger and baffle of the network card: the solder joint of the circuit board of the high-quality network card is uniform and clean, the golden finger and baffle are regular and shiny, and the distribution of various components is reasonable and compact.
8. Sound card:
The main function of the sound card is to process the sound signal and transmit the signal to the speaker or earphone, so that the latter can make sound. The purchase of sound card is somewhat similar to the purchase of network card and graphics card. We should choose large manufacturers and products with good after-sales service, and pay attention to whether the interface type matches our own motherboard. The sound quality of a graphics card is the standard to judge whether a graphics card is good or bad, including signal-to-noise ratio, sampling bits, sampling frequency, total harmonic distortion and other indicators. At present, the signal-to-noise ratio of sound cards mostly reaches 96dB, the sampling bits are more than 16bit, and the sampling frequency is more than 44.1KHz (the higher the value, the better). Theoretically, 44.1KHz can achieve CD sound quality. In addition, if buyers only use ordinary applications, such as watching CDs and playing some simple games, it is enough to buy ordinary cheap sound cards; If it is used to play large-scale 3D games, you must buy a sound card with 3D function, because 3D sound effect has become the trend of game development, and now all games begin to support it.
9. Power Supply:
Power supply is the main accessory for computer power supply. It is a device that converts AC current into DC voltage. The power supply is related to the stable operation of the whole computer, and its output power shall not be less than 250W. When purchasing power supply, pay attention to brand, output power, certification, packaging, etc.