To get to know the central processing unit (CPU), we first introduce a part of the computer called SoC very briefly. SoC, or system on a chip, is a part of a system that integrates all the components a computer needs for processing on a silicon chip. The SoC has various modules, of which the central processing unit (abbreviated as CPU) is the main component, and the GPU, memory, USB controller, power management circuits, and wireless radios (WiFi, 3G, 4G LTE, etc.) are miscellaneous components that may be necessary. not exist on the SoC. The central processing unit, which from now on and in this article will be called the processor for short, cannot process instructions independently of other chips; But building a complete computer is only possible with SoC.

The SoC is slightly larger than the CPU, yet offers much more functionality. In fact, despite the great emphasis placed on the technology and performance of the processor, this part of the computer is not a computer in itself, and it can finally be introduced as a very fast calculator that is part of the system on a chip or SoC; It retrieves data from memory and then performs some kind of arithmetic (addition, multiplication) or logical (and, or, not) operation on it.

Calling or retrieving instructions from memory (Fetch): The processor first receives these instructions from memory in order to know how to manage the input and know the instructions related to it. This input may be one or infinitely many commands that must be addressed in separate locations. For this purpose, there is a unit called PC (abbreviation of Program Counter) or program counter, which maintains the order of sent commands; The processor is also constantly communicating with RAM in a cooperative interaction to find the address of the instruction (reading from memory).

Decoding or translation of instructions (Decode): Instructions are translated into a form that can be understood by the processor (machine language or binary). After receiving the commands, the processor needs to translate these codes into machine language (or binary) to understand them. Writing programs in binary language, from the very beginning, is a difficult task, and for this reason, codes are written in simpler programming languages, and then a unit called Assembler converts these commands into executable codes ready for processor processing.

Processing or execution of translated instructions (Execute): The most important step in the processor’s performance is the processing and execution of instructions. At this stage, the decoded and binary instructions are processed at a special address for execution with the help of the ALU unit (abbreviation of Arithmetic & Logic Unit) or calculation and logic unit.

Storage of execution results (Store): The results and output of instructions are stored in the peripheral memory of the processor with the help of the Register unit, so that they can be referred to in future instructions to increase speed (writing to memory).

The process described above is called a fetch-execute cycle, and it happens millions of times per second; Each time after the completion of these four main steps, it is the turn of the next command and all steps are executed again from the beginning until all the instructions are processed.

RISC and CISC are the two starting and ending points of this spectrum in the instruction set category, and various other combinations are also visible. First, let’s state the basic differences between RISC and CISC:

As mentioned, in the design of today’s modern processors, a combination of these two sets (CISC or RISC) is used. For example, AMD’s x86 architecture originally uses the CISC instruction set, but is also equipped with microcode to simplify complex RISC-like instructions. Now that we have explained the differences between the two main categories of instruction sets, we will examine their application in processor architecture.

If you pay attention to the processor architecture when choosing a phone or tablet, you will notice that some models use Intel processors, while others are based on ARM architecture.

In 1823, a person named Baron Jones Jacob Berzelius discovered the chemical element silicon (symbol Si, atomic number 14) for the first time. Due to its abundance and strong semiconductor properties, this element is used as the main material in making processors and computer chips. Almost a century later, in 1947, John Bardeen , Walter Brattin and William Shockley invented the first transistor at Bell Labs and received the Nobel Prize.

The first efficient integrated circuit (IC) was unveiled in September 1958, and two years later IBM developed the first automated mass production facility for transistors in New York. Intel was founded in 1968 and AMD was founded a year later.

The first processor was invented by Intel in the early 1970s; This processor was called Intel 4004 and with the benefit of 2,300 transistors, it performed 60,000 operations per second. The Intel 4004 CPU was priced at 200 and had only 640 bytes of memory:

After Intel, Motorola introduced its first 8-bit processor (the MC6800) with a frequency of one to two MHz, and then MOS Technology introduced a faster and cheaper processor than the existing processors used in gaming consoles of the time, namely the Atari 2600 and Nintendo systems. Used like Apple II and Commodore 64. The first 32-bit processor was developed by Motorola in 1979, although this processor was only used in Apple’s Macintosh and Amiga computers. A little later, National Semiconductor released the first 32-bit processor for public use.

In 1993, PowerPC released its first processor based on a 32-bit instruction set; This processor was developed by the AIM consortium (consisting of three companies Apple, IBM, and Motorola) and Apple migrated from Intel to PowerPC at that time.

The difference between 32-bit and 64-bit processor (x86 vs. x64): Simply put, the x86 architecture refers to a family of instructions that was used in one of the most successful Intel processors, the 8086, and if a processor is compatible with the x86 architecture, that processor known as x86-64 or x86-32 for Windows 32 (and 16) versions bit is used; 64-bit processors are called x64 and 32-bit processors are called x86.

The biggest difference between 32-bit and 64-bit processors is their different access to RAM:

The maximum physical memory of x86 architecture or 32-bit processors is limited to 4 GB; While x64 architecture (or 64-bit processors) can access physical memory of 8, 16, and sometimes even up to 32 GB. A 64-bit computer can run both 32-bit and 64-bit programs; In contrast, a 32-bit computer can only run 32-bit programs.

In most cases, 64-bit processors are more efficient than 32-bit processors when processing large amounts of data. To find out which programs your operating system supports (32-bit or 64-bit), just follow one of the following two paths:

• Press the Win + X keys to bring up the context menu and then click System. -> In the window that opens, find the System type section in the Device specification section. You can see whether your Windows is 64-bit or 32-bit from this section.
• Type the term msinfo32 in the Windows search box and click on the displayed System Information. -> From the System Information section on the right, find the System type and see if your Windows operating system is based on x64 or X32.

The first route

The ARM architecture is designed to be as simple as possible while keeping power dissipation to a minimum. On the other hand, Intel uses more complex settings with the X86 architecture, which is more suitable for more powerful desktop and laptop processors.

Computers moved to 64-bit architecture after Intel introduced the modern x86-64 architecture (also known as x64). 64-bit architecture is essential for optimal calculations and performs 3D rendering and encryption with greater accuracy and speed. Today, both architectures support 64-bit instructions, but this technology came earlier for mobile.

When ARM implemented 64-bit architecture in ARMv8, it took two approaches to this architecture: AArch32 and AArch64. The first one is used to run 32-bit codes and the other one is used to run 64-bit codes.

ARM architecture is designed in such a way that it can switch between two modes very quickly. This means that the 64-bit instruction decoder no longer needs to be compatible with 32-bit instructions and is designed to be backward compatible, although ARM has announced that processors based on the ARMv9 Cortex-A architecture will only be compatible with 64-bit instructions in 2023. and support for 32-bit applications and operating systems will end in next-generation processors.

The differences between ARM and Intel architecture largely reflect the achievements and challenges of these two companies. The approach of optimal energy consumption in the ARM architecture, while being suitable for power consumption under 5 watts in mobile phones, provides the possibility of improving the performance of processors based on this architecture to the level of Intel laptop processors. Compared to Intel’s 100-watt power consumption in Core i7 and Core i9 processors or even AMD processors, it is a great achievement in high-end desktops and servers, although historically it is not possible to lower this power below 5 watts.

Processors that use more advanced transistors consume less power, and Intel has long been trying to upgrade its lithography from 14nm to more advanced lithography. The company recently succeeded in producing its processors with the 10nm manufacturing process, but in the meantime, mobile processors have also moved from 20nm to 14nm, 10nm, and 7nm designs, which is a result of competition from Samsung and TSMC. On the other hand, AMD unveiled 7nm processors in the Ryzen series and surpassed its x86-64 architecture competitors.

Nanometer: A meter divided by a thousand is equal to a millimeter, a millimeter divided by a thousand is equal to a micrometer, and a micrometer divided by a thousand is equal to a nanometer, in other words, a nanometer is a billion times smaller than a meter.

Lithography or manufacturing process: lithography is a Greek word that means lithography, which refers to the way components are placed in processors, or the process of producing and forming circuits; This process is carried out by specialized manufacturers in this field, such as TSMC. In lithography, since the production of the first processors until a few years ago, nanometers showed the distances of placing processor components together; For example, the 14nm lithography of the Skylake series processors in 2015 meant that the components of that processor were separated by 14nm. At that time, it was believed that the less lithography or processor manufacturing process, the more efficient energy consumption and better performance.

The distance between the placement of components in processors is not so relevant nowadays and the processes used to make these products are more contractual; Because it is no longer possible to reduce these distances beyond a certain limit without reducing productivity. In general, with the passage of time, the advancement of technology, the design of different transistors, and the increase in the number of these transistors in the processor, manufacturers have adopted various other solutions such as 3D stacking to place transistors on the processors.

The most unique feature of ARM architecture can be considered as keeping the power consumption low in running mobile applications; This achievement comes from ARM’s heterogeneous processing capability; ARM architecture allows processing to be divided between powerful and low-power cores, and as a result, energy is used more efficiently.

ARM’s first attempt in this field dates back to the big.LITTLE architecture in 2011, when the large Cortex-A15 cores and the small Cortex-A7 cores arrived. The idea of ​​using powerful cores for heavy applications and using low-power cores for light and background processing may not have been given as much attention as it should be, but ARM experienced many unsuccessful attempts and failures to achieve it; Today, ARM is the dominant architecture in the market: for example, iPads and iPhones use ARM architecture exclusively.

In the meantime, Intel’s Atom processors, which did not benefit from heterogeneous processing, could not compete with the performance and optimal consumption of processors based on ARM architecture, and this made Intel lag behind ARM.

Finally, in 2020, Intel was able to use a hybrid architecture for cores with a powerful core (Sunny Cove) and four low-consumption cores (Tremont) in the design of its 10 nm Lakefield processors, and in addition to this achievement, it also uses graphics and connectivity capabilities. , but this product was made for laptops with a power consumption of 7 watts, which is still considered high consumption for phones.

Another important distinction between Intel and ARM is in the way they use their design. Intel uses its developed architecture in the processors it manufactures and sells the architecture in its products, while ARM sells its design and architecture certification with customization capabilities to other companies, such as Apple, Samsung, and Qualcomm, and these companies They can make changes in the set of instructions of this architecture and design depending on their goals.

Manufacturing custom processors is expensive and complicated for companies that manufacture these products, but if done right, the end products can be very powerful. For example, Apple has repeatedly proven that customizing the ARM architecture can bring the company’s processors to par with x84-64 or beyond.

As mentioned earlier, standard architectures based on RISC or CISC categories or a combination of the two were designed and the specifications of these standards were made available to everyone; Applications and software must be compiled for the processor architecture on which they run. This issue was not a big concern before due to the limitations of different platforms and architectures, but today the number of applications that need different compilations to run on different platforms has increased.

ARM-based Macs, Google’s Chrome OS, and Microsoft’s Windows are all examples in today’s world that require software to run on both ARM and x86-64 architectures. Native software compilation is the only solution that can be used in such a situation.

In fact, for these platforms, it is possible to simulate each other’s code, and the code compiled for one architecture can be executed on another architecture. It goes without saying that such an approach to the initial development of an application compatible with any platform is accompanied by a decrease in performance, but the very possibility of simulating the code can be very promising for now.

After years of development, currently, the Windows emulator for a platform based on ARM architecture provides acceptable performance for running most applications, Android applications also run more or less satisfactorily on Chromebooks based on Intel architecture, and Apple, which has a special code translation tool for has developed itself (Rosetta 2) supports older Mac applications that were developed for the Intel architecture.

However, as mentioned, all three perform weaker in the implementation of programs than if the program was written from scratch for each platform separately. In general, the architecture of ARM and Intel X86-64 can be compared as follows:

During the competition between Arm and x86 over the past ten years, ARM can be considered the winning architecture for low-power devices such as phones. This architecture has also made great strides in laptops and other devices that require optimal energy consumption. On the other hand, although Intel has lost the phone market, the efforts of this manufacturer to optimize energy consumption have been accompanied by significant improvements over the years, and with the development of hybrid architecture, such as the combination of Lakefield and Alder Lake, now more than ever, there are many commonalities with processors. It is based on Arm architecture. Arm and x86 are distinctly different from an engineering point of view, and each has its own individual strengths and weaknesses, however, today it is no longer easy to distinguish between the use cases of the two, as both architectures are increasingly supported. It is increasing in ecosystems.

Another factor that affects the performance of the processor is the capacity of the processor’s cache memory or RAM; This type of RAM works much faster than the main RAM of the system due to being located near the processor and the processor uses it to temporarily store data and reduce the time of transferring data to/from the system memory.

Cache memory can be multi-layered and is indicated by the letter L. Usually, processors have up to three or four layers of cache memory, the first layer (L1) is faster than the second layer (L2), the second layer is faster than the third layer (L3), and the third layer is faster than the fourth layer (L4). . The cache memory usually offers up to several tens of megabytes of space to store, and the more space there is, the higher the price of the processor will be.

The cache memory is responsible for maintaining data; This memory has a higher speed than the RAM of the computer and therefore reduces the delay in the execution of commands; In fact, the processor first checks the cache memory to access desired data, and if the desired data is not present in that memory, it goes to the RAM.

• Level one cache memory (L1), which is called the first cache memory or internal cache; is the closest memory to the processor and has high speed and smaller volume than other levels of cache memory, this memory stores the most important data needed for processing; Because the processor, when processing an instruction, first of all goes to the level one cache memory.
• Level two (L2) cache memory, which is called external cache memory, has a lower speed and a larger volume than L1, and depending on the processor structure, it may be used jointly or separately. Unlike L1, L2 was placed on the motherboard in old computers, but today, in new processors, this memory is placed on the processor itself and has less delay than the next layer of cache, namely L3.
• The L3 cache memory is the memory that is shared by all the cores in the processor and has a larger capacity than the L1 or L2 cache memory, but it is slower in terms of speed.
• Like L3, L4 cache has a larger volume and lower speed than L1 or L2; L3 or L4 are usually shared.

The core is the processing unit of the processor that can independently perform or process all computing tasks. From this point of view, the core can be considered as a small processor in the whole central processing unit. This part of the processor consists of the same operational units of calculation and logical operations (ALU), memory control (CU), and registers (Register) that perform the process of processing instructions with a fetch-execution cycle.

In the beginning, processors worked with only one core, but today processors are mostly multi-core, with at least two or more cores on an integrated circuit, processing two or more processes simultaneously. Note that each core can only execute one instruction at a time. Processors equipped with multiple cores execute sets of instructions or programs using parallel processing (Parallel Computing) faster than before. Of course, having more cores does not mean increasing the overall performance of the processor. Because many programs do not yet use parallel processing.

• Single-core processors: The oldest type of processor is a single-core processor that can execute only one command at a time and is not efficient for multitasking. In this processor, the start of a process requires the end of the previous operation, and if more than one program is executed, the performance of the processor will decrease significantly. The performance of a single-core processor is calculated by measuring its power and based on frequency.
• Dual-core processors: A dual-core processor consists of two strong cores and has the same performance as two single-core processors. The difference between this processor and a single-core processor is that it switches back and forth between a variable array of data streams, and if more threads or threads are running, a dual-core processor can handle multiple processing tasks more efficiently.
• Quad-core processors: A quad-core processor is an optimized model of a multi-core processor that divides the workload between cores and provides more effective multitasking capabilities by benefiting from four cores; Hence, it is more suitable for gamers and professional users.
• Six-core processors (Hexa-Core): Another type of multi-core processor is a six-core processor that performs processes at a higher speed than four-core and two-core types. For example, Intel’s Core i7 processors have six cores and are suitable for everyday use.
• Octa-Core processors: Octa-core processors are developed with eight independent cores and offer better performance than previous types; These processors include a dual set of quad-core processors that divide different activities between different types. This means that in many cases, the minimum required cores are used for processing, and if there is an emergency or need, the other four cores are also used in performing calculations.
• Ten-core processors (Deca-Core): Ten-core processors consist of ten independent systems that are more powerful than other processors in executing and managing processes. These processors are faster than other types and perform multitasking in the best possible way, and more and more of them are released to the market day by day.

Let’s say you want to take 2 people from point A to B, of course a Lamborghini will do just fine, but if you want to transport 50 people, a bus can be a faster solution than multiple Lamborghini commutes. The same goes for single-core versus multi-core processing.

In recent years and with the advancement of technology, processor cores have become increasingly smaller, and as a result, more cores can be placed on a processor chip, and the operating system and software must also be optimized to use more cores to divide instructions and execute them simultaneously. allocate different If this is done correctly, we will see an impressive performance.

This is where the concept of asymmetric processor design was born. For smartphones, Intel quickly adopted a solution that some cores are more powerful and provide better performance, and some cores are implemented in a low-consumption way; These cores are only good for running background tasks or running basic applications such as reading and writing email or browsing the web.

High-powered cores automatically kick in when you launch a video game or when a heavy program needs more performance to do a specific task.

Although the combination of high-power and low-consumption cores in processors is not a new idea, using this combination in computers was not so common, at least until the release of the 12th generation Alder Lake processors by Intel.

In each model of Intel’s 12th generation processors, there are E cores (low consumption) and P cores (powerful); The ratio between these two types of cores can be different, but for example, in Alder Lake Core i9 series processors, eight cores are intended for heavy processing and eight cores for light processing. The i7 and i5 series have 8.4 and 6.4 designs for P and E cores, respectively.

There are many advantages to having a hybrid architecture approach in processor cores, and laptop users will benefit the most, because most daily tasks such as web browsing, etc., do not require intensive performance. If only low-power cores are involved, the computer or laptop will not heat up and the battery will last longer.

Hyperthreading in Intel processors and simultaneous multithreading (SMT) in AMD processors are concepts to show the process of dividing physical cores into virtual cores; In fact, these two features are a solution for scheduling and executing instructions that are sent to the processor without interruption.

Today, most processors are equipped with hyperthreading or SMT capability and run two threads per core. However, some low-end processors, such as Intel’s Celeron series or AMD’s Ryzen 3 series, do not support this feature and only have one thread per core. Even some high-end Intel processors come with disabled hyperthreading for various reasons such as market segmentation, so it is generally better to read the Cores & Threads description section before buying any processor. Check it out.

Hyperthreading or simultaneous multithreading helps to schedule instructions more efficiently and use parts of the core that are currently inactive. At best, threads provide about 50% more performance compared to physical cores.

In general, if you’re only doing active processing like 3D modeling during the day, you probably won’t be using all of your CPU’s cores; Because this type of processing usually only runs on one or two cores, but for processing such as rendering that requires all the power of the processor cores and available threads, using hyperthreading or SMT can make a significant difference in performance.

In the field of computers, botlink (or bottleneck) is said to limit the performance of a component as a result of the difference in the maximum capabilities of two hardware components. Simply put, if the graphics unit receives instructions faster than the processor can send them, the unit will sit idle until the next set of instructions is ready, rendering fewer frames per second; In this situation, the level of graphics performance is limited due to processor limitations.

The same may happen in the opposite direction. If a powerful processor sends commands to it faster than the graphics unit can receive, the processor’s capabilities are limited by the poor performance of the graphics.

In fact, a system that consists of a suitable processor and graphics, provides a better and smoother performance to the user. Such a system is called a balanced system. In general, a balanced system is a system in which the hardware does not create bottlenecks (or bottlenecks) for the user’s desired processes and provides a better user experience without disproportionate use (too much or too little) of system components.

It is better to pay attention to a few points to set up a balanced system:

• You can’t set up a balanced system for an ideal gaming experience by just buying the most expensive processor and graphics available in the market.
• Butlink is not necessarily caused by the quality or oldness of the components and is directly related to the performance of the system hardware.
• Graphics botlinking is not specific to advanced systems, and balance is also very important in systems with low-end hardware.
• The creation of botlinks is not exclusive to the processor and graphics, but the interaction between these two components prevents this problem to a large extent.