◇Five units of computer hardware
❥1. Input unit
Input units are devices that transmit data to the computer, such as keyboards, mice, card readers, handwriting pads, touch screens, etc. Data input first exists in the memory unit, and the memory unit exists in the host.
❥2. Output unit
The output unit is a device that receives the data processed by the computer, such as a printer, a display screen, etc. The data processed by the CPU must be put in the memory before being transmitted to the output unit.
❥3. System unit
The system unit contains all the hardware in the host computer, such as: CPU, graphics card, memory, etc.
❥4. Control unit, 5. Arithmetic logic unit
The control unit and the arithmetic logic unit exist in the CPU, which is also an important function of CUP.
- Two CPU architectures (categories): CISC and RISC
The CPUs of the computers we use are all types of complex instruction sets, which can perform rich tasks.
❥6. Storage unit
The storage unit is not included in the five major units, but it includes memory and auxiliary storage. The memory exists in the system unit, and the auxiliary storage includes: hard disk, floppy disk, optical disk, tape, etc.
◇Computer commonly used unit of calculation
❥1. Capacity
Capacity refers to storage capacity. Computers only recognize 0 and 1, which is binary. We call the unit of binary a bit (bit, bit). We often talk about 32-bit and 64-bit computers as this unit, so why do we say 32-bit and 64-bit computers? These two numbers represent the word length that the CPU parses each time. Obviously, the more data bits that can be parsed each time, the better the computer performance.
In the early 32-bit CPU, because the amount of data that the CPU can parse each time is not large, it does not require a large amount of memory, which results in a 32-bit CPU that can only support a maximum of 4GB of memory. Installing more memory will also be wasted because of the working speed of the CPU.
The unit of bit is too small, and there is a unit of one bit more: Byte, 1B=8b. (One byte = 8 bits) The
byte is not big enough, there are KB, M, G, T and so on in one bit.
| Binary | Decimal |
|---|---|
| 1024B=1KB | 10 ^ 3B = 1KB |
| 1024KB=1M | 10 ^ 3KB = 1M |
| 1024M=1G | 10 ^ 3m = 1g |
| 1024G=1T | 10 ^ 3G = 1T |
Generally speaking, the data capacity is binary, so the memory of 500GB is actually: 500x1024x1024x1024B. But if you buy a 500GB hard drive, the actual capacity may only be about 466GB. This is because the hard drive manufacturer uses the decimal system to make the capacity sound a little more.
❥2. Speed
The operation of the computer needs to be completed by the CPU. The speed units used by the CPU command cycle are MHz and GHz (Hz represents the number of times per second).
The speed unit is usually decimal, for example, 500GHz means 500x1000x1000x1000Hz.
The commonly used unit of the network speed we call is Mbit/s, which is how many bits are transmitted per second. When the light speed of 20M/5M that is often heard is converted into bytes, it needs to be divided by 8, which is 2.5MB/s per second. The upload or download speed is 625KB per second.
❥3. Frequency
The frequency of the computer also refers to the work efficiency of the CPU. Simply put, the frequency refers to the number of jobs that the CPU can perform per second.
The frequency unit also uses decimal. If the frequency of a CPU is 3.6GHz, it means that this CPU can perform 3.6x10^9 jobs per second.
- CPU FSB In the
early CPU architecture, another chip on the motherboard <North Bridge> was used to connect the memory and the graphics card. When multiple components are connected externally to the CPU, the same operating frequency is required, and FSB (Front Side Bus Speed) is created. At present, in order to improve performance, the CPU can bypass the North Bridge and communicate with devices such as memory and graphics cards alone.
Simply put, the FSB of the CPU is the speed of data transmission between the CPU and external components. - The frequency multiplier of the CPU
has been stretched over the speed of data transmission by external components. In order to maintain efficient work, the CPU will transmit the data to the CPU before speeding up.
The multiplication of the FSB and the multiplier is the frequency speed of the CPU.
For example: if the frequency of a CPU is 3GHz, if the external frequency is 333MHz, the multiplier is 9 times.
Overclocking: Through the setting function provided by the motherboard, the FSB or multiplier of the CPU can be modified higher. Generally, the FSB can be modified. Because the frequency is abnormal speed, blind modification may cause downtime.