The influence of cpu on computer model paper 1: computer CPU paper
CPU is the core of computer operation, and its main performance indicators include word length, main frequency, cache, front-end bus frequency, application of hyper-threading technology, supported extended instruction sets, etc. This plays a vital role in the performance of the whole computer. In the use of computers, common CPU overclocking failures, computer infection, which greatly reduces the performance of CPU, and occasionally crashes. , gradually master the main performance and troubleshooting skills of CPU, and achieve the effect of giving inferences by analogy.
Keywords: CPU performance index; Caching; Display a black screen; trouble clearing
1 Main performance indicators of computer CPU
Central Processing Unit (CPU), also known as "microprocessor" or "central processing unit", is the core of computer operation, equivalent to the "brain" in the computer system, mainly responsible for computer data operation and issuing computer control instructions, and is the "commander in chief" for controlling the operation of other devices in the computer. In the process of computer development, the development of CPU technology has always been the focus of computer technology development, and the troubleshooting of CPU is also a difficult point in computer use. We need to study hard to deepen our understanding of CPU, gradually master the troubleshooting methods and skills of CPU common faults, cooperate with CPU work, coordinate the processing speed of CPU, and achieve the effect of drawing inferences from others in use.
The "word length" of 1. 1 CPU is the main technical index indicating the performance of the arithmetic unit.
In computer technology, the number of bits of binary numbers processed by CPU in unit time is called "word length". In general, a CPU that can process 8-bit data per unit time is called an 8-bit CPU. Similarly, a 64-bit CPU can process binary data with a word length of 64 bits per unit time. Word length is the main technical index to express the performance of arithmetic unit, which is usually equal to the width of CPU data bus. The longer the CPU word length, the higher the calculation accuracy, the faster the information processing speed and the higher the CPU performance.
1.2 Relationship between CPU frequency and external frequency and CPU frequency doubling: CPU frequency refers to the working frequency when the computer is running, also called "main frequency" or "clock frequency". The frequency of the CPU represents the oscillation speed of the digital pulse signal inside the CPU and the actual running speed of the CPU, and the unit is Hz. The higher the CPU frequency, the more instructions can be completed in a clock cycle, and the faster the CPU runs.
The higher the frequency multiplication of 1.2. 1, the higher the CPU frequency. The actual running frequency of CPU is related to the external frequency and frequency doubling of CPU. Actual frequency of CPU = external frequency! Dual frequency. External frequency is the reference frequency of CPU, which is the speed at which CPU and motherboard run synchronously. The higher the external frequency speed, the more data the CPU can receive from peripheral devices at the same time, thus further improving the speed of the whole system. Frequency doubling is a parameter of the difference between the working frequency of CPU and the external frequency of the system, also known as "frequency doubling coefficient", usually referred to as "frequency doubling". With the same external frequency, the higher the frequency doubling, the higher the CPU frequency.
The higher the main frequency of 1.2.2, the faster the CPU. When we use CPU, we usually say "Pentium Ⅲ 600" and "Pentium 4 3.0". In fact, the numbers "600" and "3.0" in these models refer to the main frequency of CPU. The main frequency of CPU is generally in MHz, and the "600" in "Pentium III 600" usually means that the main frequency of CPU is 600MHz. But with the increase of CPU frequency, it is generally at GHz( 1GHz= 1000MHz). For example, 3.0 in Pentium 4 3.0 means that the working frequency of CPU is 3.0GHz, which is 3000MHz. Generally speaking, the number of instructions completed in a clock cycle is fixed, so the higher the main frequency, the faster the CPU.
1.3 The larger the cache capacity, the higher the performance:
1.3. 1 Cache is used to store data of CPU and memory.
Provide high-speed data buffering during exchange. When the CPU wants to read data, it will first look for data in the cache. If it finds it, it will read data directly from the cache. If it cannot find it in the cache, the CPU will read data from the main memory. CPU cache is generally divided into L 1 cache and L2 cache.
1.3.2 Impact of Level 1 Cache and Level 2 Cache on CPU Performance L 1 Cache is also called Level 1 Cache (L 1 Cache) to temporarily store some instructions and data, so that the CPU can quickly obtain the needed data. L 1 cache runs synchronously with CPU, and its cache capacity has great influence on the performance of CPU. __L2Cache is also called L2 cache, and its capacity and frequency also have great influence on the performance of CPU, and its function is coordination.
The difference between CPU running speed and memory access speed. L2 cache is the largest part of the total number of CPU transistors. Due to the high cost of L2 cache, the capacity of L2 cache is generally used as the division standard of high-end and low-end CPU products. At present, the L2 cache of CPU is as low as 64KB and as high as 4MB.
Front-end bus frequency 1.4 is more representative than external frequency: Front-end bus frequency is a concept put forward by AMD when it introduced K7CPU, and many people always mistake this term for another name of external frequency. In fact, external frequency usually refers to the connection speed between CPU and motherboard. This concept is based on the oscillation speed of digital pulse signal, and the front-end bus frequency refers to the actual speed of data transmission, that is, the amount of data transmission that CPU can receive every second. For example, the external frequency 100MHz means that the digital pulse signal oscillates 100000 times per second, while the front-end bus frequency 100 1MHz means that the acceptable data transmission capacity of the CPU is 100MHz per second! 64 bits /8 bits/byte = 800 megabytes. In terms of processor speed, the front-end bus is more representative than the external frequency.
The manufacturing process of 1.5 CPU is directly related to the electrical performance of CPU;
1.5. 1 CPU has a higher working frequency, and the smaller the line width, the lower the CPU power consumption and heat generation. At present, the manufacturing technology of mainstream products of Intel has reached 0.065 m level. After the CPU is manufactured, it is a silicon chip (or integrated circuit) smaller than 1cm2, which needs to be packaged and pins (or pins) installed before it can be inserted into the motherboard. Generally, the values in Socket478 and Socket939 refer to the number of pins of the CPU. There are two general CPU packages: ceramic package and resin package.
Application of 1.5.2 Hyper-threading (HT) is a technology specially designed for Pentium4 by Inter Company. Hyper-threading is a synchronous multithreading execution technology. Intel processors with Hyper-Threading Technology can be logically simulated as two tasks. Applying Hyper-Threading Technology to computer system can improve the performance of the whole machine by more than 25%.
The extended instruction set supported by 1.6 plays an important role in improving the efficiency of CPU: instruction set is the command used by CPU to calculate and control the system, and it is a series of instructions that match the hardware circuit. Instruction set is one of the important indexes to evaluate CPU performance. At present, the instruction sets are MMX, SSE, SSE2, SSE3 and "3DNow!" AMD's. Wait a minute. MMX (Multimedia Extensions) instruction set was developed by Intel Corporation, including 57 multimedia instructions. Usually, these instructions can process multiple data at the same time, which improves the CPU's ability to process graphics, video and audio. SSE(Streaming SIMDExtensions) instruction set is an extension of MMX instruction set, which was first used by Intel Corporation for Pentium 3 processors. SSE2 supports SIMD processing of double-precision floating-point numbers for 64-bit CPU. SSE3 is a set of instructions added by Intel Corporation in the latest Pentium 4 Prescott processor, which is used to enhance the multimedia performance of Pentium 4 CPU and help to enhance the hyper-threading function of Intel CPU. “3DNow！” Extended instruction set
It is used in AMD's K6- 2, K6- 3 and Athlon( k7) processors. With the cooperation of software, the 3D processing performance can be greatly improved. “3Dnow！” Instruction set is the earliest three-dimensional instruction set.
2 Troubleshooting of common CPU faults in computer use
2. 1 Failure phenomenon: Generally speaking, CPU is not prone to failure, but due to overclocking or unstable voltage operation and different CPU manufacturing processes, the CPU will not work normally, the display will suddenly go black, and it will be invalid after restarting, and even more seriously, it will burn out the CPU. (1)CPU overclocking is the favorite thing of DIY family. Some CPUs do not have overclocking ability but insist on overclocking. Some CPUs have little overclocking margin, but they work outside the rated frequency. As a result, the computer can't work normally and often crashes. Because the CPU is overclocked and hard overloaded, it may be a failure caused by overclocking instability. If you touch the CPU with your hand after booting, it is found to be very hot, and the fault may be here. The solution is: users can find the external frequency and frequency doubling jumper of CPU, and after gradually reducing the frequency, start the power supply, the system will return to normal, and the display screen will display it. It is also possible that after overclocking, the cooling fan may rotate normally when the computer is started, but the hard disk indicator light will not respond only once, and the display will remain in standby state. Because you can't enter the BIOS setup option at this time, you can only downgrade the CPU. The specific method is to open the chassis to find the jumper on the motherboard to discharge CMOS, and restart the system after discharging CMOS. It is worth noting that memory size, hard disk speed, graphics card speed,
In particular, the performance index of CPU plays a vital role in the performance of the whole computer, and it is not advisable to blindly pursue the high speed of CPU first-level cache and second-level cache and the front-end bus frequency. (2) Abnormal voltage causes CPU to burn out. The common fault phenomenon is that the screen is black after booting, only the CPU fan is turning, and there is no POST. Solution: according to the fault phenomenon, eliminate the power failure. The fan is turning after the boot, which means that the computer is powered on. But if you can't check yourself, you won't hear the sound of "Didi". At this time, it is suspected that the motherboard or CPU is faulty. After the preliminary judgment, the replacement method is adopted for confirmation. First of all, find a good computer with the same configuration, remove the CPU of this computer and replace it with a faulty computer. If you can boot into the system normally after booting, it means that the fault of this computer is the CPU. If you look at the CPU carefully, you will find a black place at the corner of the needle, indicating that the CPU is burned out because of unstable voltage.
2.2 After the computer is infected with the virus, the performance of the CPU drops obviously, even accompanied by death.
Machine phenomenon: (1) The fault may be caused by virus infection, excessive disk fragmentation or excessive CPU temperature. The solution is to use anti-virus software to kill virus first, and then use the "disk defragmentation" program attached to Windows to clean it up. If the problem cannot be solved, open the chassis and check whether the fan of the CPU radiator rotates after power-on. If it does not rotate, please replace it with a new radiator. (2) Why does worm attack make CPU utilization as high as 100%? Fault phenomenon: the hard disk indicator flashes all the time after starting for a period of time, and at the same time,
The running speed of the system becomes very slow, and the "Task Manager" window shows CPU utilization 100%. You can continue to use it only after restarting. But after a while, it's still the same. It can be seen from the fault description that the computer system is infected with some kind of worm virus. In general, when a large program is not running, the instantaneous occupancy rate of CPU cannot be 100%. When a worm attacks, it will fill the remaining system resources. At this point, users can check which program occupies the most CPU resources in the task manager window. If it is a strange program, users are advised to use anti-virus software (preferably the latest anti-virus library) to thoroughly check the system. If the problem cannot be solved, it is best to reinstall the operating system and install a virus firewall. In this way, the problem can be completely solved.
2.3 CPU fan does not turn, resulting in computer crash: failure phenomenon: a computer.
The computer crashed shortly after booting into the system, and the fault still exists after restarting the computer. Solution: Open the chassis and check the operation of the equipment in the chassis. It is found that the CPU fan rotates slowly and is in a non-rotating state. Therefore, it is considered that the reason for the restart may be that the CPU fan can not dissipate heat due to abnormal operation, which makes the CPU temperature rise sharply and eventually crash. Because it is a sudden black screen, it may be that the hardware is loose and the contact is poor. You can open the chassis, plug in the hardware again, and then turn it on. There may be something wrong with the graphics card, because judging from the indicator light of the monitor that there is no signal output, it is no problem to check the graphics card by "replacement method", so the monitor may be faulty at this time.
I checked it with the "replacement method" and found no problem. Then I checked the CPU and found that the pins of the CPU were a little dark green, which was a sign of rust. It seems that this is the problem, because there is condensation on the refrigeration sheet. It must be that the surface temperature of the cooling plate is too low, which leads to the CPU being in a humid environment for a long time. Over time, there will be too many rust spots, resulting in poor contact, thus causing this failure. After finding the problem, remove the CPU fan, lubricate the fan and clean the dust on the fan, and then reinstall the CPU fan. After the boot, the CPU fan rotates normally and the crash phenomenon is eliminated. You can also take out the CPU, carefully wipe each pin with an eraser, and then take off the cooling plate on the heat sink and clean it. Finally, install the CPU and refrigeration chip and turn it on, and you can start it normally.
Computers will always have some faults for various reasons. Especially when encountering common failures of CPU, we should fully understand the main performance indicators of CPU, analyze the causes of failures, master common troubleshooting methods and skills, and avoid computer black screen, crash and other failures caused by CPU failures.
References:
Xiong Qiaoling, Lu, Gao. Computer assembly and maintenance skills training
[M]。 Beijing: Science Press, 2007.
Tan xian. Computer assembly, maintenance and troubleshooting [M]. Beijing: Machinery Industry Press, 2007.
[3] Editor of Netcrown Technology. Computer first aid, backup and recovery, BIOS and registry design [M]. Beijing: Machinery Industry Press, 2007.
Zhang Jingsheng. The use and maintenance of desktop computer [M]. Beijing: National Defense Industry Press, 2007. [5] __ Work and repair the Red Sea. Computer assembly and maintenance [M]. Beijing: China Federation of Industry and Commerce Press, 2007.
The Influence of cpu on Computer Model Paper 2: Principles of Computer Composition -CPU Paper
CPU is the core of computer operation, its importance is equivalent to the human brain, and it plays a vital role. The main performance indicators of CPU are word length, main frequency, cache, front-end bus frequency, application of hyper-threading technology, supported extended instruction set, etc. This plays a vital role in the performance of the whole computer. We need to understand the CPU from its development history, working principle, troubleshooting and other aspects, in order to achieve a comprehensive understanding of the CPU.
Keywords: troubleshooting of historical working principle of CPU
The principle of computer component-CPU
Wu min
CPU is the core of computer operation, which is as important as human brain and plays a vital role.
The main attributes of CPU include word length, frequency, cache, FSB, hyper-threading technology and supporting instruction set expansion, which play an important role in the performance of the whole computer. Understand the development history of CPU, understand the working principle and troubleshooting of CPU, and achieve a comprehensive understanding of CPU.
CPU history; Working principle; debugging
introduce
CPU is the abbreviation of central processing unit, also known as microprocessor. With the advent of the network era, network communication, information security and information home appliances will become more and more popular, and CPU is an indispensable part of all these information products. CPU is mainly composed of arithmetic unit and controller, which is the core part of microcomputer hardware system and plays the role of controlling the whole microcomputer system.
The performance of CPU usually determines the grade of a computer.
There are two main companies producing CPU chips in the world: Intel and AMD. The CPU produced by Intel has always occupied a considerable market. At present, the CPU produced by Intel mainly includes Celeron series, Pentium series and Core series. AMD's CPU occupies a considerable market share. The CPU produced by AMD mainly includes the Flash Dragon series and the Speed Dragon series.
Coordination determines the overall performance of the computer. CPU is mainly composed of arithmetic unit, controller, register group and internal bus. The register group is used to store the operands and intermediate data after the instruction is executed, and the operator completes the operations and operations specified in the instruction.
The development of CPU is very rapid. It took less than twenty years for personal computers to develop from 8088(XT) to Pentium 4 era.
197 1 Intel 4004, the world's first microprocessor 1974 Intel 8008, the first 8-bit microprocessor; 1974 Intel 8080, the first real microprocessor; 1978 Intel 8086, 16-bit microprocessor; Intel 80186; 1982 Intel 80286;
1985 Intel 80386, a new generation of 32-bit core microprocessor; 1989 Intel 80486; 1993 Pentium;
In the production process, the original 8088 integrated 29,000 transistors, while Pentium III III integrated more than 2,865,438+10,000 transistors. The running speed of CPU, in MIPS (millions of instructions per second), 8088 is 0.75MIPS, which has exceeded 1000MIPS in high-energy operation.
Introduction and historical development of 1 CPU
The external composition of CPU: control unit, storage unit (register, cache) and logical operation unit.
The external composition of CPU: chip, metal shell (protecting CPU and increasing heat dissipation area) and pins (fixing CPU and connecting circuit).
CPU is the core component of the computer, which processes all the data in the computer, enabling the computer to complete various functions and all the components to work.
From the initial development to the present, CPU can be divided into 4-bit microprocessor, 8-bit microprocessor, 16-bit microprocessor, 32-bit microprocessor and 64-bit microprocessor according to the word length of processing information. Basically, it can be said that the development of personal computers is advancing with the development of CPU.
197 1 year, the world's first microprocessor Inter 4004 appeared, with 2300 transistors integrated inside; 1978 Inter 16-bit processor 8086 and its mathematical coprocessor 8087 were launched at the same time; 1979 introduces Inter8088, which contains 27,000 transistors, and the external data bus is reduced to 8 bits. It is also the first time to use it on IBM PC, which indicates the arrival of microcomputer era. 1982 Inter also introduced 80286 of 16-bit and 13.4 kilo internal transistors, and the time-frequency increased from 6MHZ to 20. 1985 32-bit processor 80386 was introduced, and the time-frequency reached 12.5MHZ or above; In 1989, 80486 of1.2000 transistor appeared, with a time-frequency of 90MHZ, and its performance was four times higher than that of 386. Pentium era is coming 1993, Pentium 1, the world's first 586-level Processor, 365,438+million transistors, time-frequency 200MHZ 1996 Pentium pro, 5.5 million transistors, the processing speed is twice that of the first generation; At the same time, secondary memory was adopted for the first time, and Pentium MMX was introduced in the same year, and the cache of L 1 was doubled; 1997, Pentium Pro combined with MMX, and Pentium 2 appeared, which greatly improved its performance. Pentium 3 appears in 1998, with a first-level cache of 2KB and a second-level cache of 5 12KB, which greatly improves the security performance; Pentium 4 was introduced in 2000, and its main frequency exceeded 1.7GHZ. After that, the development of dual-core and quad-core Inter processors represented the development of CPU, including many other products, such as AMD.
2 working principle and process of CPU
2. The working principle of1CPU
Regardless of appearance, the main working principle of CPU is to execute a series of instructions stored in so-called programs. What is discussed here is the device designed according to the general von Neumann architecture. Programs are stored in computer memory in the form of a series of numbers. Almost all von Neumann CPUs can be divided into four stages: extraction, decoding, execution and write-back.
The first stage is to extract and retrieve instructions (values or a series of values) from the program memory. The program counter specifies the location of the program memory, and the program counter stores a numerical value for identifying the current program location. In other words, the program counter records the trace of CPU in the current program. After the instruction is fetched, the PC adds a storage unit [iwordlength] according to the instruction length. Instructions are usually fetched from relatively slow memory, causing the CPU to wait for instructions to be sent in. This problem is mainly discussed in the cache and pipeline architecture of modern processors.
The CPU determines its execution behavior according to the instructions extracted from the memory. In the decoding stage, instructions are broken down into meaningful fragments. According to the definition of CPU instruction set architecture (ISA), numerical value is interpreted as instruction [isa]. Part of the instruction value is the operation code, which indicates which operations to perform. Other numerical values usually provide necessary information for instructions, such as the operation target of addition operation. Depending on the addressing mode, the object of this operation can provide a constant value (i.e., an immediate value) or a spatial addressing value: a register or a memory address. In the old design, the instruction decoding part of CPU was an unchangeable hardware device. However, in many abstract and complex CPUs and ISAs, microprograms are often used to help convert instructions into various forms of signals. These microprograms can often be rewritten in the finished CPU, which is convenient to change the decoding instructions.
After the extraction and decoding stage, it enters the execution stage. At this stage, it is connected to various CPU components that can perform the required operations. For example, if an addition operation is required, the ALU will be connected to a set of inputs and a set of outputs. The input provides the values to be added, and the output will contain the sum result. ALU contains circuits that perform simple general operations and logical operations (such as addition and bit operations) at the output. If the result of the addition operation is too large for the CPU to handle, you can set the overflow flag in the flag register.
In the final stage, reply. In a certain format
The result is simply written back. The operation results are usually written into the internal registers of the CPU for quick access by subsequent instructions. In other cases, the operation result may be written into the main memory with slower speed but larger capacity and cheaper price. Some types of instructions will operate program counters without directly generating result data. These are often called "jumps" and bring loop behavior, conditional execution (through conditional jumps) and function [jumps] in the program. Many instructions also change the status bits of the flag register. These flags can be used to influence the behavior of programs because they often show the results of various operations. For example, use the "compare" instruction to judge the size of two values, and set a value on the flag register according to the comparison result. This flag can be used to determine program trends through subsequent jump instructions.
After writing back the result data after executing the instruction, the value of the program counter will be incremented, and the whole process will be repeated, and the next sequential instruction will be fetched normally in the next instruction cycle. If the jump instruction is completed, the program counter will be modified to the address of the jump instruction, and the program will continue to execute normally. Many complex CPUs can fetch multiple instructions at once, decode them and execute them at the same time. This part generally involves the "classic RISC pipeline", which is actually rapidly popularized in many electronic devices that use simple CPU (usually called single chip microcomputer).
The digital representation of CPU is a design choice, which affects the working mode of equipment. Some early digital computers used electrical models to represent common decimal (based on 10 decimal) digital system numbers. There are also some rare computers that use ternary to represent numbers. Modern CPU almost always uses binary to represent numbers, so that numbers can be represented by physical quantities of two values, such as [binaryvoltage] and so on.
Related to digital representation is the size and accuracy of the numbers that CPU can represent. In the case of a binary CPU, a bit refers to a meaningful bit in the number processed by the CPU. The number of bits used by CPU to represent numbers is usually called word length, bit width, data path width or integer precision (as opposed to floating-point numbers). In fact, integer precision sets a hardware limit on the range of integer values that CPU executable software can use. Integer precision also affects the amount of memory that the CPU can address. For example, if a binary CPU uses 32 bits to represent memory addresses and each memory address represents an octet, the addressable capacity of the CPU is 232 octets or 4GB. The above is a simple description of CPU address space. Usually, the actual CPU design uses more complex addressing methods, such as paging technology, in order to address more memory with the same integer precision.
Higher integer precision requires more lines to support more digital bits, so the structure is more complex, larger, more energy-consuming and usually more expensive. Therefore, although there are many CPUs with higher precision in the market, such as 16, 32, 64 or even 128, it can still be seen that the application software is executed on a 4-bit or 8-bit microcontroller. Simpler single-chip computers are usually cheaper, consume less energy and therefore generate less heat. These are the main considerations in designing electronic equipment.
2.2 the running process of CPU
Data flows from the input device through the memory, waiting for CPU processing. The information to be processed is stored in bytes, that is, in the unit of 8-bit binary numbers or 8 bits 1 unit, which can be data or instructions. Data can be binary characters, numbers, colors and so on. Instructions tell the CPU how to process data, such as adding, subtracting or shifting. Assume that the data in memory is the simplest original data. First, the instruction pointer will inform the CPU that the instruction to be executed will be placed in the storage location in the memory. Because each storage unit in the memory has a number (called an address), data can be taken out according to these addresses and sent to the control unit through the address bus. The instruction decoder takes the instruction from the instruction register IR, translates it into a form that the CPU can execute, and then decides what necessary operations are needed to complete the instruction. It tells the arithmetic logic unit (ALU) when to calculate, when the instruction reader gets the numerical value, and when the instruction decoder translates the instruction. If data is sent to the ALU, the data will perform arithmetic operations and other operations specified in the instruction. When the data is processed, it will return to the register and continue to run through different instructions or send to the data buffer through DB bus. Basically, this is how the CPU performs three basic tasks: reading data, processing data and writing data into memory. But under normal circumstances, an instruction can contain many operations executed in a clear order. The job of CPU is to execute these instructions. After completing an instruction, the control unit of the CPU will tell the instruction reader to read the next instruction from the memory for execution. This process is repeated quickly and continuously, and one instruction after another is executed quickly, producing the results you see on the monitor. While processing so many instructions and data, due to the time difference between data transmission and CPU processing, there will definitely be confusion in processing. In order to ensure that every operation happens on time, the CPU needs a clock to control every action that the CPU performs. The clock is like a metronome, it constantly sends out pulses, which determines the rhythm and processing time of the CPU.
References:
Principles of electronic computer composition Jiang Benshan Beijing Institute of Technology
Principles of Computer Organization, 2nd Edition, edited by Tang Shuofei, Higher Education Press, 2008.438+0.
Introduction to Computer Theory Yu Long Author: Introduction to Computer Science by Wang Electronics Industry Press Author: Principle and Application of Microcomputer edited by Xiao Jinli, Mechanical Industry Press, 2003- 1