What is the difference between a bus frequency and a system bus frequency?

The bus transmits data once by a clock cycle, and there are :

1 bus operating frequency = a * 1 bus clock frequency.

That is, bus operating frequency = bus clock frequency a

Clock Frequency = 1 Clock Cycle Operating Frequency = 1 Bus Cycle The former refers to the clock frequency of the machine, and the latter refers to various on the bus.

The frequency of operation, specifically how many times to transmit data in 1 second, 1 bus cycle = n * clock cycle, n size is defined according to the question.

That's what it means.

When all the sub-rail data is processed, it must be controlled by the bus when it wants to flow out!!

Make the final output changes!

【1.Main frequency] The main frequency is also called the clock frequency, the unit is MHz, which is used to indicate the computing speed of the CPU. The main frequency is determined by the external frequency and the frequency doubling, and its calculation formula is the main frequency of the external frequency * frequency doubling.

The external frequency is the working frequency of the system bus; The frequency doubling refers to the multiple of the difference between the CPU external frequency and the main frequency. For example, if the external frequency of the Intel Pentium4 processor is 133 and the frequency is 23, the main frequency is 133*23

2.External frequency] The external frequency is the base frequency of the CPU, and the unit is also MHz. The external frequency is the speed of synchronous operation between the CPU and the motherboard, and in most of the current computer systems, the external frequency is also the speed of synchronous operation between the memory and the motherboard.

3.Front-side bus] The frequency of the front-side bus directly affects the exchange speed of direct data between the CPU and the memory. Since the maximum bandwidth of data transmission depends on the width and frequency of all simultaneously transmitted data, i.e. the amount of data transferred (bus frequency * data bandwidth) 8.

The difference between the frequency of the external frequency and the front-side bus: The speed of the front-side bus refers to the speed of data transmission, and the external frequency refers to the speed of synchronous operation between the CPU and the motherboard. For example, the 100MHz external frequency refers to the digital pulse signal at **10 million times per second:

The 100MHz FSB means that the acceptable data transfer amount of the CPU per second is 100MHz*64bit (8byte bit) 800MB s.

4.Frequency doubling coefficient] The frequency doubling coefficient refers to the relative proportional relationship between the CPU main frequency and the external frequency. At the same external frequency, the higher the doubling, the higher the frequency of the CPU.

But in fact, under the premise of the same external frequency, the CPU itself with high frequency doubling is not of great significance. This is because the data transmission speed between the CPU and the system is limited, and the CPU that blindly pursues high frequency doubling and obtains a high main frequency will have an obvious "bottleneck" effect - the ultimate speed of the CPU to get data from the system cannot meet the speed of CPU operation.

5.Memory Bus Speed] The CPU processes data from memory, and the main memory is memory. Generally, the data placed on the external memory (disk or various storage media) must pass through the memory and then enter the CPU for processing.

Therefore, the memory bus speed of the channel between the CPU and the memory is very important for the overall system performance. Since there is a greater or lesser difference in the speed of operation between the memory and the CPU, there is a L2 cache to coordinate the difference between the two, and the memory bus speed is the communication speed between the CPU and the L2 cache and memory.

6.Expansion bus speed] expansion bus refers to the local bus installed on the computer system such as VESA or PCI bus, when we open the computer, we will see some slot-like things, these are expansion slots, and the expansion bus is the bridge between the CPU and these external devices.