What Is a CPU?
CPU stands for central processing unit, and in a strict sense, it is one of the components of a microprocessor that plays a central role in arithmetic processing. However, in the current situation, CPU is more often used almost synonymously with a microprocessor.
The components of a computer can be categorized into CPU, memory, graphics and HDD drive units, and input/output devices, such as Ethernet communication interfaces.
In the early days of computers, these components were disparate and were combined to make a computer.
Among these components, the CPU is a device that reads and executes a set of instructions stored in memory one by one based on the means of reading and executing instructions it has inside.
With the subsequent rapid development of semiconductor technology, the memory, graphics, and various interface functions that were previously outside of the CPU have been incorporated into the CPU, along with the progress and sophistication of semiconductor microfabrication, contributing greatly to the miniaturization and weight reduction of devices.
Usage of CPUs
CPUs are installed in all computers.
From supercomputers to high-performance computers for business use, consumer computers, and even the notebook PCs, smartphones, and tablet devices that we often use in our daily lives, all contain CPUs, although the scale of these devices differs.
CPUs are also found in a wide variety of consumer and professional devices.
These include televisions, recorders, audio equipment, cars, motorcycles, and various measuring instruments for professional use. Many of the CPUs installed in these devices are also called single-chip microcomputers, and they contribute to the miniaturization of devices by incorporating peripheral hardware and other components that are optimized for their respective fields and applications.
Principle of CPUs
The initial role of CPUs was to read instructions from memory, decode them, and execute them.
Execution means performing operations of addition, subtraction, multiplication, and division, and returning the results to memory.
Inside the CPU, there is a predefined set of instructions that can be understood and what must be done for each instruction. The instructions in memory are sequentially read by the CPU from the smallest address in memory and executed one after another.
According to the results of the operations, data is output to or read from peripheral devices.
In addition, if a graphics function is built in, data is written to the graphics. The graphics function is then displayed on a connected LCD display or monitor.
If an Ethernet communication function is built in, it takes in packet data sent to itself on the network, analyzes and calculates the data internally, and outputs the data back to the network.
CPU Architecture
CPUs have different basic designs, called architectures, depending on the product. The architecture is the most fundamental part of a CPU and is designed to determine how instructions are processed at the hardware level.
CPUs use the main memory and internal cache to perform operations, but the processing methods and operation rules differ depending on the architecture. Since these differences affect the application level, which is a more superficial layer, the OS and various applications must be designed in accordance with the CPU architecture.
There are generations of CPU architectures, which are generally updated every few years. Since architecture has a significant impact on CPU performance, it is a good idea to check which architecture the CPU is based on when selecting a CPU.
CPU Heat Exhaustion
To maximize the performance of a CPU, heat removal is very important. To prevent this, it is necessary to devise a way to exhaust heat.
Generally, a fan is attached to the CPU to exhaust heat, and grease is applied to the contact points between the CPU and the fan to improve thermal conductivity. This improves the heat removal performance of the fan. The grease needs to be reapplied periodically to maintain the performance.
Instead of attaching a fan to the CPU, a water-cooling method, called water cooling, is sometimes used. The water-cooling method is more effective in cooling and effective for PCs with high specifications. However, it should be noted that water cooling is expensive and there is a risk of coolant leakage in the event of a malfunction.
In addition to exhausting heat from the CPU itself, it is also important to exhaust heat from the case to the outside so that heat does not accumulate inside the case. If parts are densely packed inside the case or the amount of air exhausted from the case to the outside is small, no matter how much the CPU is cooled, only limited effects can be obtained.