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What is a CPU, processor or microprocessor

A CPU (acronym for “Central Processing Unit“, “central processing unit” in English), also known as microprocessor, or modern processor; It is the main hardware component of an electronic device that is responsible for carrying out all the calculations and processes for the operation of the PC, calculator, television, watch and any electronic device.

The CPU It is the main brain of any electronic device, put simply. If an electronic device does not have a CPU, the device cannot do anything because it cannot start or end processes in the system.

Processors history

In June 1945, John von Neumann in his work “First Draft of a Report on the EDVAC” (“First Draft of a Report on the EDVAC” in English), designed the first stored program computer capable of storing programs in high-speed memory. This allowed the program to be changed by rewriting the contents of memory, instead of having to physically rewire the computer for each program. EDVAC was also capable of calculating in binary, rather than decimal, and could perform instructions of various types.

EDVAC

Although it was not the first stored program computer that was manufactured, as before came the “Manchester Small-Scale Experimental Machine” (“Manchester Small Scale Experimental Machine” in English), which was a prototype of a stored program computer, in June 1948.

During the 50s, the first general-purpose digital computers appeared, made with vacuum tubes that acted as active electronic components. They consisted of basic logic circuits such as gates and flip-flops.

In the late 1950s, transistors began to replace vacuum tubes as parts of CPUs, allowing for smaller computers. Solid-state circuits evolved to be lower cost and mass produced. This finally made vacuum tubes were replaced by transistors when manufacturing computers.

Intel 4004 CPU

In 1971, Intel released the first commercial Intel 4004 processor, which integrated all CPU functions on a single chip small size designed for calculators, which was called a microprocessor. In 1978, Intel introduced the Intel 8086 to the market, which would be the first microprocessor to use the x86 architecture that is still used today.

CPU internals

A CPU is made up of the following parts:

  • Control unit: Digital circuit that extracts instructions from memory, deciphers them, and executes them.
  • Arithmetic Logic Unit: (ALU) The ALU (acronym for “Arithmetic Logic Unit“) is a digital circuit that carries out logical, mathematical and arithmetic operations.
  • Records: CPU memory that allows the results of small and frequently used instructions to be saved. There are data, memory, general purpose, floating point, constant and specific purpose registers.

What types of CPU are there according to their architecture?

There are 2 types of CPUs according to their architecture, which are RISC and CISC. The RISC architecture (acronym for “Reduced Instruction Set Computer","Reduced instruction set computer” in English) is based on simple and custom-designed instructions to reduce the execution time of instructions, and thus be faster and more efficient. RISC CPUs use ARM designs, which are licensed to other manufacturers and are present in the SOCs of mobile phones, tablets and some laptops.

A CISC CPU (acronym for “Complex Instruction Set Computer","Complex instruction set computer" In english is a complex instruction CPU architecture, which reduces the number of instructions in software and ignores the number of cycles per instruction. This type of architecture is used by Intel and AMD.

If you want to know AMD CPUs, we have a AMD Ryzen CPU listing.

Instruction set of a CPU

The Instruction Set of a CPU are the commands and operations that the CPU can understand and execute for its operation. These instructions allow programmers and the operating system to have an interface to communicate with the CPU. The most common types of operations on a CPU are the following:

  • Data transfer: They copy data from a source, and move it to a destination. The most used are”move","store","load","move block","move multiple","exchange","clear","set","push"And"pop".
  • Arithmetic instructions: Operations performed by the ALU, which can change flags and condition indicators. The most used are “add","add with carry","subtract","subtract with borrow","increments","decrement","multiply","divides","extend","deny"And"absolute".
  • Comparison instructions: They are usually used before an instruction with conditions, and can modify the flags. The most used are “compare"And"test".
  • Logical instructions: They perform boolean operations, and can officiate flags. The most used are “and","or","xor", Y "not".
  • Arithmetic or logical shift instructions.
  • Bit instructions: They check a bit and reflect its value in the indicator.
  • Control instructions: They can modify the normal execution sequence of a program. They are qualified in unconditional jump, conditional jump, calling subroutines and interrupt management.
  • Entry and exit instructions: Transfer instructions that have as their destination or origin a port of an input or output device.
  • Control instructions: Instructions that stop program executions, as well as allowing and disabling them. They are used so that the processor checks which processes are or are not being executed.

Logic gates of a CPU

All operations that a CPU performs are performed in binary using logic gates based on 0 and 1. Logic gates use binary because “on” (also known as “logical 1”) and “off” (“logical 0”) are the only data any electronic device can receive input, or output. The logic gates of the transistors that make up the microprocessor of a CPU can perform the following operations:

  • OR: It outputs a logical zero when at least one of the input pins is a 1. If all the input values ​​are 0 then the output value will be 0.
  • AND: The output is 1 if all input values ​​are logic 1s. If at least one of the cases is 0, the output will be 0.
  • XOR: The is 1 when only one of the input pins is a 1 and the rest of the input pins have a value of 0. If this is not met, the output is a logical zero.
Logic gates of a CPU

Another type of logic gates are negated logic gates, which invert their output value through an inverter. The inverter is known as NOT, which is not a logic gate because it is responsible for changing the signal from 0 to 1. This inverter is used to create the negated logic gates, with the following operations:

  • NOR: reverse gate of the OR gate. The output is 1 when all input signals are 0, and it will be 0 if at least one of the input signals is 1.
  • NAND: reverse gate of the AND gate. Its output is always logic 1, except when all input values ​​are 1. When all input values ​​are 1, the output is 0.
  • NOR: inverted XOR gate. The output is 0 when at least one of the inputs is 1. Thus, the output is 1 when all the inputs are 0.

Various questions about the CPU

Where does the CPU store data?

A microprocessor or CPU stores smaller processes in registers and cache memory; The most complex processes are saved in RAM, and the files and data that must be saved permanently are stored on a storage system such as a hard drive or SSD.

How to see CPU usage?

CPU usage can be checked using Windows Task Manager software. This allows you to see the Windows processes that are using the CPU. With the task manager we can see what percentage of the CPU is being used, by what programs, and even how much CPU they are using. This is useful if you notice that your computer is slow and you want to eliminate processes that are consuming a lot of CPU.

Screenshot of Task Manager to view CPU usage

What is CPU overclocking and what is it for?

Overclocking is the practice of forcing a CPU to frequencies above its factory values. Overclocking is done by removing the temperature limiters that the CPU has, and using more intense CPU cooling systems.

Overclocking a CPU using liquid nitrogen

Overclocking is used to speed up for large workloads. There is also a community of overclockers who, through benchmarks and monitoring software, seek to push CPUs to higher frequencies.

It should be said that CPU overclocking has its risks. There are CPUs and motherboards made to facilitate overclocking. But the components are exposed to deterioration due to the fact that they have exceeded their own factory limits for correct operation.

Can a CPU have a GPU?

A CPU can integrate a GPU within it, and would be considered an iGPU (acronym for “Integrated Graphics Processing Unit”, or integrated graphics processing unit). Integrated GPUs are commonly known as “integrated graphics".

Intel CPU with an AMD IGPU
Intel CPU with an AMD IGPU

If a CPU integrates an iGPU, it will be able to output video through the motherboard. An iGPU is common in laptops and pre-built computers medium or low ranges, because they do not need a dedicated graphics card.

What is the clock frequency of a CPU?

The frequency of a CPU is the speed at which it performs operations. It is typically expressed in gigahertz (GHz), which is equivalent to one billion hertz. A higher CPU frequency indicates potentially higher performance, but it is not the only factor that influences your overall performance.

What is the cache of a CPU?

The cache of a CPU is divided into the following levels and category:

  • L1 cache: A unique cache block for each core
  • L2: Cache Shared between the same group of cores, but to which the cores take longer to reach.
  • L3 cache: Cache shared by all CPU cores, generally larger in size, but it is the cache that takes the longest to reach.

The higher the cache level, the slower it will be, because it has to be available to more CPUs.

The CPU cache allows you to store very light, very repetitive processes, so that the CPU does not have to calculate them in RAM. AMD with the Ryzen X3D series of CPUs has stacked several layers of cache memory to increase the cache capacity of the CPU, thereby achieving better CPUs for gaming.

What is AMD laminated cache or 3D cache?

AMD Laminated Cache is a way of mounting a CPU cache, debuted in the AMD Ryzen 7 5800X3D model. The intention behind this laminated cache is to offer more cache memory to the CPU by offering more layers of L3 cache, so that the CPU itself can access more memory for simple and repetitive tasks.

Render of an AMD Ryzen 7 5800X3D CPU

It is intended for use in games, primarily to reduce latency. Since the instructions being sent to the game require CPU usage, more fast access memory will allow for lower latency and not have to switch to RAM.

What is thermal paste needed for?

Thermal paste is needed to create a physical bond between the CPU die and your computer's heatsink, thereby transmitting heat from the CPU to the heatsink to prevent the CPU from overheating.

Syringe applying thermal paste to a cpu

When the heatsink is separated from the CPU, the contact of the thermal paste deteriorates and must be reapplied.

What is an Intel Hybrid Architecture CPU?

A hybrid architecture CPU is a CPU that integrates cores of different sizes and performance levels. On the 12th Generation of Intel Core hybrid architectures were released They are made up of performance cores for large processes and cluster efficiency cores for smaller processes. The most powerful cores are no longer used for very light tasks, because the efficiency cores do. Thus, the performance cores can be dedicated to doing the most complex tasks.

What influences a generation of a CPU?

A generation of a CPU influences performance, power consumption and hardware compatibility. Both AMD and Intel offer new generations of CPUs on an almost annual basis.

In a generation step of CPUs, they may opt for a lithography of fewer nanometers and thus be more energy efficient. They may include at the hardware level compatibility with new video codecs, or hardware protocols such as new generations of PCIe or RAM memory.

What happens if the processor is at 100?

If the processor is at 100, it means that it is at 100% of its capacity. You are already at maximum processing capacity, and close to maximum capacity. When this happens, the CPU begins to slow down so as not to reach critical temperature.

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Benjamin Rosa

Madrileño whose publishing career began in 2009. I love investigating curiosities that I later bring to you, readers, in articles. I studied photography, a skill that I use to create humorous photomontages.

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