The basic hardware includes arithmetic unit, controller, memory, input and output devices, etc. The home computer we see usually consists of a host, a monitor, a keyboard, a mouse and speakers.
Arithmetic unit, controller, memory, etc. All of them are installed in the mainframe case, so they can't be seen from the outside without opening the case; Keyboard and mouse are input devices, while monitors, speakers and printers are output devices. Of course, computer hardware is far more than that, as well as CD burners and scanners.
How many kb is 1M?
Everyone should know that whether it is network files, broadband bandwidth or mobile Internet traffic, its unit is M (megabytes). Many friends usually use 5 yuan to pack 30M traffic on their mobile phones, so it is enough to browse some mobile phone webpages online. So many novice friends often ask me how many kilobytes is 1M or how big is 1M?
If you often use the computer to surf the Internet, you may know this concept very well, because we often download songs and some software online. Generally speaking, the size of an MP3 music file is about 4M. The size of a film is about 200M-600M, which depends on the length and clarity of the film; There are also broadband issues that people often mention, such as a 4M telecom broadband, which involves M, so how many Kb is 1M? The answer is as follows:
KB MB GB TB refers to the unit of memory size.
They all have B. Let's start with B. B is the basic unit of computer storage (bytes), 1 English character is 1 byte, which means 1B, and 1 Chinese character is two characters, which is 2B.
Let's say that K means thousands, and KB is 1000 bytes, but computer operation is different from mathematics, it is 1024 bytes, 1KB, so it is 1024B= 1KB.
Besides, m, m means trillion, and the operation is similar. 1024 is a single digit, which means 1024KB= 1MB.
Then g, and so on, 1024 MB = 1 GB.
To sum up,1024b =1kb; 1024 KB = 1 MB； 1024 MB = 1 GB
In general, the symbol MB of M unit Chinese pronunciation is abbreviated as M, and its conversion unit is: 1MB= 1024KB, abbreviated as1m =1024 K.
The unit greater than m is G, the unit less than m is K, and the multiple between them is 1024. The specific conversion relationship is as follows:
1G= 1024M
1M= 1024K
1K= 1024B (bytes)
Units greater than GB are TB, PB, EB, ZB, YB, etc. Because the capacity above TB is quite large, it is rarely encountered in computers.
Tip: How many Kb is 1M? I believe you can say 1024KB at will, but it's actually very simple, just a concept, which can be applied flexibly!
What is the main frequency of computer cpu? Is the higher the main frequency of cpu, the better?
When we discuss computer hardware, we often mention the word "the main frequency of computer cpu", but what is the main frequency of computer cpu? I believe many novice friends don't understand it very well. Let's get to know it together!
In electronic technology, pulse signal is a continuous pulse signal with a certain voltage amplitude and a certain time interval. The time interval between pulse signals is called period; The number of pulses generated per unit time (such as 1 sec) is called frequency.
The so-called frequency is a measurement name that describes the number of pulses that appear in a unit time for periodic cyclic signals (including pulse signals); The standard unit of measurement of frequency is hertz. The system clock in the computer is a typical pulse signal generator, and its frequency is quite accurate and stable.
Frequency is represented by "f" in mathematical expression, and the corresponding units are: hertz (Hz), kilohertz (kHz), megahertz (MHz) and gigahertz (GHz). Where 1GHz= 1000MHz, 1MHz= 1000kHz, 1kHz= 1000Hz. Calculate the time unit of the pulse signal period and the corresponding conversion relationship: s (seconds), ms (milliseconds), μs (microseconds) and ns (nanoseconds), where: 1s= 1000ms, 1ms = 1000ms,.
The main frequency of computer CPU indicates the oscillation speed of digital pulse signal in CPU, which is not directly related to the actual computing power of CPU. There is a certain relationship between the main frequency and the actual running speed, but there is no definite formula to quantify the numerical relationship between them, because the running speed of CPU depends on the performance indicators of CPU pipeline (cache, instruction set, CPU bits, etc.). ).
Because the main frequency of computer CPU does not directly represent the running speed, in some cases, it is likely that the CPU with higher main frequency will actually run at a lower speed. For example, most of AMD's AthlonXP series CPU can achieve the CPU performance of Intel's Pentium 4 series CPU at a low frequency, so AthlonXP series CPU is named after PR value. Therefore, the main frequency is only one aspect of CPU performance, not the overall performance of CPU, which should be paid attention to when installing our computer.
The main frequency of computer CPU does not represent the speed of CPU, but improving the main frequency is very important to improve the running speed of CPU.
Assuming that a CPU executes an operation instruction in a clock cycle, when the CPU runs at 100MHz, it will be twice as fast as when it runs at 50MHz. Because the clock cycle of 100MHz is half of that of 50MHz, that is, the CPU working at 100MHz only needs 10ns to execute an operation instruction, which is half of that of 20ns working at 50MHz, and the natural operation speed is doubled. However, the overall running speed of the computer depends not only on the running speed of the CPU, but also on the running speed of other subsystems. Only when the main frequency is improved, the running speed of each subsystem and the data transmission speed between subsystems can be improved, and the overall running speed of the computer can be really improved.
Since CPU is made on a semiconductor silicon wafer, the components on the silicon wafer need to be connected by wires. Because the wire is required to be as thin as possible at high frequency, it can reduce stray interference such as distributed capacitance of the wire and ensure the correct operation of CPU. Therefore, the limitation of manufacturing process is one of the biggest obstacles to the development of CPU main frequency. Therefore, improving the working frequency of CPU is mainly limited by the production process.
What is the main frequency of computer cpu? That is, the CPU clock speed at which the CPU core works. How many megahertz is a certain CPU? This megahertz is the "CPU main frequency". Many people think that the main frequency of CPU is its running speed, but it is not.
Is the cpu frequency as high as possible? This is not necessarily because the main frequency is only one aspect of CPU performance and does not represent the overall performance of CPU. There are also external frequency, FSB frequency, memory and so on. If they don't match well, it's like a highway. When it is wide, it is very popular with everyone. When it is narrow, there will be traffic jams, and all the data will be stuck there, which is what people call a bottleneck. In a big bottle, it will be poured out bit by bit through a narrow bottle mouth, so all the hardware should be reasonably matched.
For example, most of AMD's AthlonXP series CPU can achieve the CPU performance of Intel's Pentium 4 series CPU at a low frequency, so AthlonXP series CPU is named after PR value. Therefore, the main frequency is only one aspect of CPU performance and does not represent the overall performance of CPU. The main frequency of CPU does not represent the speed of CPU, but increasing the main frequency can improve the operation of CPU.
What is the power supply circuit?
The power supply circuit is an important part of the motherboard, and its function is to convert the current transmitted by the host power supply into voltage, convert the voltage into a core voltage value acceptable to the CPU, and make the CPU work normally, and shape and filter the current transmitted by the host power supply to filter out all kinds of clutter and interference signals, so as to ensure the stable work of the computer. The main part of the power supply circuit is generally located near the CPU slot of the motherboard.
Linear power supply mode
This is the main board power supply mode many years ago, which is realized by changing the conduction degree of the transistor. The transistor is equivalent to a variable resistor and is connected in series in the power supply circuit. Because the variable resistor flows through the same current as the load, it consumes a lot of energy, which leads to the temperature rise and the voltage conversion efficiency is low. Especially in the power supply circuit that needs large current, linear power supply cannot be used. At present, this power supply mode has long been eliminated.
Switching power supply mode
This is a widely used power supply method at present. The PWM controller IC chip provides pulse width modulation and sends out pulse signals to turn on MOSFET 1 and MOSFET2 in turn. Chokes L0 and L 1 are used as energy storage inductors, and together with the connected capacitors, an LC filter circuit is formed.
Its working principle is: when the voltage at both ends of the load (such as the voltage required by CPU) is to be reduced, the external power supply charges the inductor through the switching action of MOSFET to reach the required rated voltage. When the voltage across the load rises, the external power supply is disconnected through the switching effect of MOSFET, and the inductor releases the energy just charged, and then the inductor becomes the power supply to continue to supply power to the load. With the consumption of energy stored in the inductor, the voltage across the load begins to decrease gradually, so it is necessary to charge the external power supply through the switching effect of MOSFET. By analogy, in the process of continuous charging and discharging, it will become a stable voltage and will never increase or decrease the voltage at both ends of the load. This is the biggest advantage of switching power supply. In addition, because the MOSFET works in the switching state, its internal resistance when turned on and leakage current when turned off are very small, so its own power consumption is very small, which avoids the problem that the resistor part of the linear power supply in series in the circuit consumes a lot of energy. This is also the working principle of the so-called "single-phase power supply circuit".
General single-phase power supply can provide the maximum current of 25A, but the commonly used CPU has already exceeded this figure. The power of P4 processor can reach 70-80W, and the working current even reaches 50A. Single-phase power supply can not provide enough reliable power, so now the power supply circuit design of motherboard adopts two-phase or even multi-phase design. It is a schematic diagram of two-phase power supply, which is easy to understand. It is a parallel connection of two single-phase circuits, so it can provide double current supply, which is more than enough to meet the current CPU demand in theory. But the above is only pure theory, and many practical factors need to be added, such as the performance of switching elements and the resistance of conductors, which are all factors that affect Vcore. In practical application, there are efficiency problems in the power supply, and the electric energy will not be converted into 100%. Generally speaking, the consumed electric energy will be converted into heat and emitted, so any common regulated power supply is the part with higher temperature in electrical components. It should be noted that the higher the temperature, the lower its efficiency. In this way, if the conversion efficiency of the circuit is not very high, then the circuit using two-phase power supply may not meet the needs of CPU, so there are three-phase or even more power supply circuits. However, it also brings the complexity of motherboard wiring. If the wiring design is unreasonable at this time, it will affect the stability of high frequency work and a series of problems will appear. At present, many mainstream motherboard products in the market use three-phase power supply circuit, which can provide enough power for CPU. However, due to the lack of circuit design, the stability of the motherboard is limited to some extent in extreme cases. If we want to solve this problem, we must make greater efforts in circuit design and wiring, and the cost will rise.
The reason why the power supply circuit adopts multiphase power supply is to provide more stable current. The pulse square wave signal sent from the control chip PWM is shaped into a DC-like current through the LC oscillating circuit. The high potential time of square wave is very short. The more phases, the closer the quasi-DC is to DC.
The power supply circuit plays a very important role in the performance and stability of the computer, and is an important performance parameter of the motherboard. When purchasing, you should choose products with excellent design and sufficient materials from mainstream manufacturers.
What does notebook mean, notebook is notebook?
The English name is NoteBook, commonly known as notebook computer. Portable, notebook computer, NB for short, also known as laptop or notebook computer (Hong Kong and Taiwan call it notebook computer 1), is a small, portable personal computer, usually weighing 1-3 kg. Its development trend is smaller and lighter, but stronger. Like a netbook, also known as a netbook, the main difference from a PC is that it is easy to carry.
Major brands and manufacturers
Asus notebook computer
Hp notebook computer
Dell notebook computer
Toshiba notebook
Sony notebook
Acer notebook
Shenzhou notebook
BENQ (benq) notebook
Samsung notebook
thinkpad
Apple notebook
What does cdkey mean and how to collect it?
CDKEY refers to the serial number required for software registration. Most commercial software needs to install serial number (or CDKEY code), which is usually marked on the product packaging or manual. The installation serial number (SN, serial number) and CDKEY code form a specific product registration code after software installation. Users can also use this registration code to register with software vendors to obtain various technical support services in the future.
CDKEY only refers to the serial number required for software registration.
CD, key, key. This is the key to the CD. The technical term is registration code, which is actually a password. But the difference between this password and ordinary password is that it can only be entered by reading the disk, not from the keyboard, even if others know it. General online banking needs it to ensure the security of customer information.
Simply put, cd key is the software registration code, that is, the password or serial number of the software installed on the CD. For example, the system installation CD has a long row of boxes for you to enter the number when installing the system.
According to the name, you should know something. A CD is a kind of optical disc. KEY means key, which is the key to open the CD. The popular answer is the registration code or serial number! The technical term is registration code, which is the registration code and key of software.