The main frequency of a microcomputer largely determines its running speed. What does it mean?

The main frequency refers to the "microprocessor clock operating frequency". The main frequency is the clock frequency of the CPU. The operation of the computer is executed step by step under the control of the clock signal. Each clock signal cycle completes one step of the operation. The level of the clock frequency largely reflects the speed of the CPU, that is, the operation of the computer. speed. There is a certain relationship between the main frequency and the actual computing speed. The main frequency indicates the speed at which the digital pulse signal oscillates in the CPU; but the main frequency is only one aspect of the CPU's performance and does not represent the overall performance of the CPU.

The operating environment of this tutorial: Windows 7 system, Dell G3 computer.

The main frequency of a microcomputer largely determines the running speed of the computer. It refers to the "microprocessor clock operating frequency".

The main frequency is the clock frequency of the CPU. The operation of the computer is executed step by step under the control of the clock signal. Each clock signal cycle completes one step of the operation. The level of the clock frequency reflects the speed of the CPU to a large extent. speed.

The main frequency of the CPU is the clock frequency at which the CPU core works (CPU Clock Speed). What is usually said is the MHz of a certain CPU, and this MHz is the "main frequency of the CPU". Many people think that the main frequency of a CPU is its running speed, but this is not the case. The main frequency of the CPU indicates the speed at which the digital pulse signal oscillates in the CPU, and has no direct relationship with the actual computing power of the CPU (that is to say, the main frequency of the current CPU will not directly affect the computing power of the CPU. It does not mean that it has no impact on the computing power. Impact. Just because no matter how low the current CPU frequency is, it is much higher than other hardware frequencies such as memory).

There is a certain relationship between the main frequency and the actual computing speed, but it is not a simple linear relationship. The main frequency indicates the speed at which the digital pulse signal oscillates in the CPU. The computing speed of the CPU also depends on various performance indicators such as the CPU's pipeline and bus. In other words, the main frequency is only one aspect of CPU performance and does not represent the overall performance of the CPU.

Characteristics of main frequency

There is a certain relationship between main frequency and actual computing speed, but there is no definite formula that can quantify the two or numerical relationship, because the computing speed of the CPU also depends on the performance indicators of various aspects of the CPU pipeline (cache, instruction set, number of CPU bits, etc.). Since the main frequency does not directly represent the computing speed, under certain circumstances, a CPU with a higher main frequency may have a lower actual computing speed. For example, most of AMD's AthlonFX series CPUs can achieve the higher frequency CPU performance of Intel's Pentium 4 series CPUs at lower clock speeds, so the AthlonFX series CPUs are named after PR values. Therefore, the main frequency is only one aspect of CPU performance and does not represent the overall performance of the CPU.

The main frequency of the CPU does not represent the speed of the CPU, but increasing the main frequency is crucial to increasing the CPU's computing speed. For example, assuming a CPU executes an arithmetic instruction in one clock cycle, when the CPU runs at a main frequency of 100MHz, it will be twice as fast as when it runs at a main frequency of 50MHz. Because the 100MHz clock cycle takes up half the time compared to the 50MHz clock cycle, that is, the time required for a CPU working at a 100MHz main frequency to execute an operation instruction is only 10 ns, which is half shorter than the 20 ns when working at a 50 MHz main frequency. Natural computing The speed is twice as fast. However, the overall running speed of the computer not only depends on the CPU computing speed, but also is related to the operation of other sub-systems. Only by increasing the main frequency, the running speed of each sub-system and the data transmission speed between sub-systems can be improved. After it is improved, the overall running speed of the computer can really be improved.

Increasing the CPU working frequency is mainly limited by the production process. Since the CPU is manufactured on a semiconductor silicon wafer, wires are required to connect the components on the silicon wafer. Under high-frequency conditions, the wires are required to be as thin and short as possible, so as to reduce stray interference such as wire distributed capacitance. To ensure that the CPU operation is correct. Therefore, the limitation of manufacturing process is one of the biggest obstacles to the development of CPU frequency.

When it comes to processor clock speed, we need to mention two closely related concepts: multiplier and FSB. FSB is the base frequency of the CPU, and the unit is also MHz. The FSB is the speed at which the CPU and the motherboard run synchronously, and in most computer systems the FSB is also the speed at which the memory and the motherboard run synchronously. In this way, it can be understood that the FSB of the CPU is directly connected to the memory. pass to achieve a synchronous operating state between the two; the frequency multiplier is the multiple of the ratio of the main frequency and the external frequency. Main frequency, external frequency, multiplier, their relationship formula: main frequency = external frequency × multiplier. Early CPUs did not have the concept of "frequency multiplication". At that time, the main frequency and the speed of the system bus were the same. With the development of technology, the speed of CPU is getting faster and faster, and accessories such as memory and hard disk are gradually unable to keep up with the speed of CPU. The emergence of frequency multiplier solves this problem. It allows components such as memory to still work at a relatively low speed. Under the system bus frequency, the main frequency of the CPU can be infinitely increased by frequency multiplication (theoretically). We can think of the FSB as a production line in the machine, and the frequency multiplier is the number of production lines. The production speed of a machine (main frequency) is naturally the speed of the production line (FSB) multiplied by the number of production lines. (multiplier). Manufacturers have basically locked the multiplier. To overclock, the only way to overclock is to start with the FSB. By matching the multiplier and the FSB, you can set the jumpers on the motherboard or set soft overclocking in the BIOS, thereby partially improving the overall performance of the computer. So when buying, try to pay attention to the FSB of the CPU.

Frequency and speed

The relationship between frequency and speed: Generally speaking, the number of instructions completed in one clock cycle is fixed, so the higher the main frequency, the higher the frequency of the CPU. The speed is getting faster. However, since the internal structures of various CPUs are also different, the performance of the CPU cannot be completely summarized by the main frequency. But the frequency of the CPU can determine the grade and price level of the computer. Take Pentium 4 2.0 as an example. Its main operating frequency is 2.0GHz. What does this mean?

Specifically, 2.0GHz means that it will generate 2 billion clock pulse signals every second, and each clock signal period is 0.5 nanoseconds. The Pentium 4 CPU has 4 pipeline computing units. If the load is even, the CPU can perform 4 binary addition operations in 1 clock cycle.

This means that the Pentium 4 CPU can perform 8 billion binary addition operations per second. However, such amazing computing speed cannot fully serve users. The computer hardware and operating system themselves also consume CPU resources. However, the Athlon XP processor adopts the PR nominal method. The conversion calculation formula between the nominal frequency and the actual frequency of the Athlon XP processor with a front-side bus frequency of 266MHz disclosed by AMD is as follows: Nominal frequency = 3 × actual frequency / 2-500 actual frequency =2×nominal frequency/3 333 For example, the actual frequency of Athlon XP 2100 is 1733MHz=2×2100/3 333.

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