- 1. Computer: a tool to assist human brain
- 2. Composition of computer hardware
- 3. power supply
- 5. memory
- 6. Classification of computer use
- 7. Introduction to common Internet servers
- 8. Server classification
1. Computer: a tool to assist human brain
Nowadays people touch computers almost all the time! Whether it’s a desktop computer, a laptop computer, a tablet computer, a smart phone, etc., these things are all computers. Although there are so many contacts, do you know what are the components in the computer? In the case of table machines, what elements are contained in the computer case? What can different computers be used for? What electrical appliances around you contain computer related components inside? Let’s talk about these things!
The so-called computer is a kind of computer, and the computer is actually: “receiving the user’s input instructions and data, and processing them through the mathematical and logical units of the central processor to generate or store useful information”. Therefore, as long as there are input devices (whether keyboard or touch screen) and output devices (such as computer screen or printing directly from a printer), you can input data to make the machine generate information, that is a computer.
Well, according to this definition, do you know what is a computer? In fact, it includes simple addition, subtraction, multiplication and division computers for general stores, mobile phones for phone calls, GPS for driving, ATM for withdrawing money, desktop PC for class, notebook PC for going out (including notebook and netbook), tablet computers and smart phones that are very popular in recent years (around 2015), and even In the future, there may be popular single version computers (xapple PI, banana PI, raspberry PI,) and smart watches, even more smart wearable computers, etc., all of which are computers!
2. Composition of computer hardware
As for the hardware components of the computer, you can actually observe your desktop computer to analyze. According to the appearance, this guy can be divided into three parts, namely:
- Input unit: including keyboard, mouse, card reader, scanner, tablet, touch screen, etc;
- Host part: This is the system unit, protected by the host shell, which contains a pile of boards, CPU and main memory, etc;
- Output unit: such as screen, printer, etc
We mainly input some data into the host through input devices such as mouse and keyboard, and then process it into charts or articles by the host function, and then transmit the results to output devices such as screen or printer. What are the components in the mainframe? If you’ve ever taken apart the computer case (including your smart phone)! ）In fact, the most important part of the host is a host board, on which the CPU, main memory, hard disk (or memory card) and some interface card devices are installed. Of course, most smart phones weld these components directly on the motherboard instead of inserting cards!
The focus of the whole host is the central processing unit (CPU). The CPU is a chip with specific functions, which contains microinstruction set. If you want the host to perform any special functions, you need to refer to whether the CPU has relevant built-in microinstruction set. Because the work of CPU mainly lies in management and operation, it can be divided into two main units in CPU: arithmetic logic unit and control unit. Among them, arithmetic logic unit is mainly responsible for program operation and logic judgment, while control unit is mainly responsible for coordinating the work of peripheral components and units.
If you don’t know the operation process of the computer very well, super brother has a simple idea to think about it. Suppose the computer is a human body, where does each component correspond to? Think like this:
CPU = brain melon seed: everyone can do different things (difference of micro instruction set), but they mainly judge and control the activities of various parts of the body through the brain melon seed;
Main memory = the block of data being considered placed in the brain: in the actual process of activity, our brain seeds need to be analyzed by external stimulus data (such as light, environment, language, etc.), so the temporary storage place of these interactive data is the main memory, which is mainly used to provide information for brain seeds to judge.
Hard disk = memory block of memory placed in the brain: different from the main memory just now, the main memory is to provide information for the brain to think about and deal with at present, but some trivial life or other things that do not need to be dealt with immediately, just put the memory in the brain first as memory! That’s the hard disk! The main purpose is to record the important information so that these important experiences can be used again in the future;
Motherboard = nervous system: just like the human nerve, it connects all important components, including the activities of hands and feet, which are conducted to the hands and feet through the nerve (motherboard) after the command is issued by the head melon seeds!
All peripheral equipment = hands, feet, skin, eyes, etc. that the human body communicates with the outside world: just like hands and feet, it is an important key for the interaction between the human body and the outside world!
Display card = image in the brain: turn the stimulation from the eyes into image and present it in the brain, so the data source generated by the display card is also controlled by CPU.
Power = heart: all components must be able to operate with enough power supply! This power supply is like the heart. If the heart is not strong enough, the whole body cannot move! Is the heart unstable? Of course, your body may be intermittent – unstable!
3. power supply
Since it is the heart of the human body, to ensure the power supply, we need a good quality power supply. In the production environment, a single core server is better to use dual power AB lines.
One connected to 220V circuit, one connected to UPS (uninterruptible power supply)
Common brands: Intel, AMD, want to be human brain
It is a buffer device between CPU and disk, also called temporary memory (storing data). When power is off, data is lost
In general, when a program is running, it will be scheduled to execute in memory. After the server is shut down or the program is shut down, the data will be released from memory.
6. Classification of computer use
Knowing the basic composition and peripheral devices of the computer, and knowing that there are many kinds of CPUs in the computer, what we want to know is how to classify the computers? There are many types of computers. If we classify them by their complexity and computing power, they can be divided into these categories:
Supercomputer is the fastest running computer, but its maintenance and operation costs are also the highest! It is mainly used in projects requiring high-speed computing. For example, national defense and military affairs, weather prediction, space science and technology are widely used in simulation fields. For details, please refer to the introduction of national high speed network and Computing Center http://www.nchc.org.tw! For the world’s fastest top 500 supercomputers, please refer to: http://www.top500.org.
Large computers usually have several high-speed CPUs. Although they are not as powerful as supercomputers, they can also be used to process large amounts of data and complex operations. For example, the mainframe of large enterprises, the national stock exchange and other enterprises that need to process millions of data every day, or the database server of large enterprises and so on.
Minicomputers still have the feature of large computers supporting multiple users at the same time, but the host can be placed in the general workplace, without the need for special air conditioning places like the first two large computers. It is usually used for scientific research, engineering analysis and plant process management.
The price of workstation is much cheaper than that of mini computer. It is designed for special purpose. Before the performance of personal computer has been improved to the current situation, the performance / price ratio of workstation computer is better among all computers, so it is quite common in academic research and engineering analysis.
Personal computers belong to this part of computer classification, which is also the main goal of this chapter! The smallest size, the lowest price, but the function is all five internal organs! It can be roughly divided into table type, note type and so on.
If only in terms of efficiency, the current personal computer efficiency is fast enough, even faster than the computer operation speed above the workstation level! However, workstation computers emphasize the stability of improper computers, and the calculation process should be completely correct, so the design considerations of computers above workstation level are not the same as that of personal computers! That’s why computers above workstation level are more expensive.
7. Introduction to common Internet servers
- Dell (used by most companies)
- IBM (Baidu, bank, government) (expensive)
The server: The server refers to the computer system that can provide some services to other machines in the network. Compared with ordinary PC, the server refers to the high-performance computer. The high-performance of the server with higher stability and security requirements is reflected in its high-speed operation ability, long-term reliable operation and strong data throughput capacity
8. Server classification
It includes mainframe, minicomputer and UNIX server. It is expensive and closed, but it has strong stability and performance. It is mainly used in the core systems of large enterprises such as finance and telecommunication.
That is to say, PC server is usually used in small and medium-sized enterprises because of its low price, good compatibility, poor stability and insecurity.
The hosting server in the computer room is charged according to the thickness of the server. Each cabinet has a limited specification. 16 1U servers can be placed in the standard cabinet. If your server is too thick and too large, the number of servers that can be placed in the cabinet is less
1U unit is = = unit = = thickness is 4.45cm
- Necessary components of computer (CPU, hard disk, memory, power supply)
- Server > personal desktop – more stable