The main frequency is the clock frequency of the CPU. Simply put, it is the working frequency of the CPU. Generally speaking, the number of instructions completed in one clock cycle is fixed, so the higher the main frequency, the faster the CPU. However, since the internal structures of various CPUs are also different, the performance of the CPU cannot be completely summarized by the main frequency. As for the FSB, it is the operating frequency of the system bus; and the frequency multiplier refers to the multiple of the difference between the CPU FSB and the main frequency. The formula is: main frequency = external frequency × multiplier.

"Frequency" is a very common technical parameter that is used in many places, especially in the introduction of hardware. Frequency is an important indicator to measure the running speed of the system. A high frequency indicates that the system runs fast, but different devices have different frequencies. Please see the text introduction below.

There is a rectangular crystal oscillator element wrapped in metal on the motherboard. When the motherboard is powered on, it will produce electromagnetic oscillation and generate a high-frequency electronic pulse signal. However, these pulses are not accurate enough and do not match the frequency required by the computer. Therefore, these original frequencies need to be input to the clock frequency generator chip near the crystal oscillator component to shape and divide the original frequency, and then change it into the frequency required by the computer. Various bus operating frequencies. The bus in the computer adopts a hierarchical structure, and the operating frequency is gradually reduced. The first level is the data transmission channel between the CPU and the Northbridge chip, which is the system front-side bus frequency; the second level is the data transmission channel between the memory and the Northbridge chip, which is the memory bus frequency; the third level is the data transmission channel between the AGP graphics card and the Northbridge chip. , that is, the AGP bus frequency; the fourth level is the data transmission channel between PCI, ISA equipment and the Southbridge chip, that is, the PCI bus frequency.

The main frequency of the CPU is the clock frequency of the CPU. Simply put, it is the working frequency of the CPU. The formula is: main frequency = external frequency × multiplier. Among them, the FSB is the bus clock frequency; and the frequency multiplier refers to the multiple of the difference between the CPU FSB and the main frequency.

Generally speaking, the number of instructions completed in one cycle is fixed, so the higher the main frequency, the faster the CPU. 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, which means that it will generate 2 billion clock pulse signals every second, and each clock signal period is 0.5ns. 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. But such an amazing budget speed cannot fully serve users. The computer hardware and operating system itself also consume CPU resources. Q#xtd_

However, AMD's Athlon XP processor adopts the PR nominal method. The conversion 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+333H1

For example, Athlon XP 210 The actual frequency is 1733MHz=2×2100/3+333.

Front Side Bus (FSB) is the line connecting the CPU and the Northbridge chip. Before Pentium 4, the system front-side bus frequency and CPU FSB were the same. The situation is different for Pentium 4 and Athlon processors.

The Pentium 4 processor uses a quadruple data transfer mode technology similar to the AGP 4× working principle. For example, Pentium 4 3.06GHz uses a 133MHz FSB, so its front-side bus frequency is 533MHz=133×4 (Note: There are some relatively fixed standard data in the hardware, especially in terms of frequency and capacity. These data have standard meanings. Sometimes it's not so accurate, like here 133×4=532, but wherever you look at the introduction, you won't see the number 532MHz, but 533. That's the reason. In fact, the frequency itself is not particularly accurate. For example, when using the Pentium 4 2.4BGHz processor under normal conditions, you will find that its actual working frequency is not 2.40GHz, but 2.41GHz. This is because its FSB has reached 133.95MHz, so 533 is like that The frequency actually represents a standard, or a grade, which is used to distinguish it from other standards or grades, and does not fully have the meaning of the number itself. Don't be surprised by this).

Similarly, on AMD Athlon (called Athlon in Chinese), Athlon XP, and Duron (called Duron in Chinese) series processors, a method is used that can transmit data on both the upper and lower edges of the pulse signal. technology, AMD calls it "double front-side bus." For example, AMD Athlon 900 uses a 100MHz FSB, but its front-side bus is 200MHz.

The main types of memory currently used include PC133 SDRAM, DDR266/333/400 DDR SDRAM (also known as PC2400/2700/3200 DDR SDRAM), PC800 RDRAM, etc. I should note the difference between memory clock frequency and memory bus frequency. The memory clock frequency is very important to the overall system performance. The memory clock frequency refers to the frequency at which the memory is working, which is generally equivalent to the bus clock frequency; while the memory bus frequency refers to the frequency of data transmission in the memory.

For example, the memory clock frequency of PC133 SDRAM is 133MHz. It can only transmit data on the rising edge of the clock pulse, which means that only 1 data can be transmitted in one clock cycle, and the data access cycle is about is 7ns, so the PC133 SDRAM memory bus frequency is also 133MHz; DDR SDRAM memory can transmit data on the rising edge and falling edge of the clock pulse at the same time, so DDR SDRAM can transmit 2 data in one clock cycle, when the memory clock frequency is 133MHz , the memory bus frequency is 266MHz, and the data access cycle is about 3ns; the PC800 RDRAM memory clock frequency is 400MHz, and both the rising and falling edges of the clock can be used to transmit data. If a dual-channel memory bus is used, the memory bus frequency reaches 800MHz. (As an aside, the labeling of DDR SDRAM is a little more confusing than others. There are labels such as DDR400 and PC3200. In fact, they are the same. The difference is that the memory bus is used when labeling the former. frequency, and the latter is marked with the memory bus bandwidth, that is, the bandwidth of DDR400 memory is 3200MB/s, but PC133 and PC800 are still marked with bus frequency)

AGP (Accelerated Graphics Port, graphics acceleration interface ) interface is a new type of bus dedicated to high-speed connections between processors and graphics cards. Just like when the popularity of graphical interface operating systems caused the bandwidth of ISA graphics cards to become a bottleneck, when some applications based on 3D graphics that require high display performance became As a trend, the bandwidth of PCI graphics cards inevitably begins to appear stretched. Here I would also like to introduce to you the difference between AGP clock frequency and AGP bus frequency.

The bit width of AGP is 32 bits like PCI, but the AGP clock frequency is twice that of PCI (ie 66MHz). It is achieved through the frequency division technology of the motherboard. From this, we can also know that the AGP clock frequency is not fixed, but depends on the bus clock frequency, which is the CPU FSB. When the bus clock frequency is 66MHz, 100MHz, or 133MHz, the motherboard will use frequency division technology to keep the AGP clock frequency at 66MHz. When the FSB is increased to a non-standard frequency, such as 125MHz, the AGP clock frequency will work at 83.3MHz.

The AGP bus frequency is also based on the AGP clock frequency, which changes with different specifications of AGP. Under AGP 1×, the AGP bus frequency and AGP clock frequency are both 66MHz; AGP 2× uses a double frequency transmission technology similar to DDR, so the bus frequency of AGP 2× reaches 133MHz, while the AGP clock frequency is still 66MHz; AGP 4 × adopts QDR (Quad Data Rate) quadruple frequency transmission technology, so the bus frequency of AGP 4× reaches 266MHz, while the AGP clock frequency is still 66MHz; AGP 8× adopts ODR (Octal Data Rate) eight times frequency transmission technology , so the bus frequency of AGP 8× reaches 533MHz, while the AGP clock frequency is still 66MHz. It can be seen that the standard of AGP clock frequency has not changed, which is 66MHz. It is said that the standard of the next generation AGP will change the AGP clock frequency.

The PCI sound card, PCI network card, IDE hard disk, and IDE optical drive in the computer all work under the PCI bus. The PCI bus frequency and PCI clock frequency are both 33MHz, which is also achieved through the motherboard's frequency division technology. When the bus frequency is 66MHz, 100MHz, or 133MHz, the motherboard will use frequency division technology to maintain the PCI bus operating frequency of 33MHz. When the external frequency is increased to a non-standard frequency, such as 125MHz, the PCI bus will operate at an operating frequency of 41.6MHz. . As a result, many components must work at non-rated frequencies, and whether they can operate normally depends on the quality of the product itself.

At this time, whether the hard disk can hold up is the most critical, because after the PCI bus frequency is increased, the data exchange speed between the hard disk and the CPU is accelerated, which is very likely to cause abnormal reading and writing, resulting in a crash. On the other hand, if all devices are fine, then a higher PCI bus frequency can significantly improve the system's operating speed.