The bus is a set of transmission lines that transmit information in one or more source components to one or more destination components. It is a popular saying that a common connection between multiple components is used to transfer information between individual components. The bus frequency is often described at the speed represented by MHz. There are many types of bus, and the English name of the front-end bus is Front Side Bus, which is usually represented by FSB, which is the bus connected to the North Bridge chip. The front end bus frequency of the computer is determined by the CPU and the North Bridge chip.
The North Bridge chip is responsible for contact with the largest data throughput such as memory, graphics card, and connects to the South Bridge chip. The CPU is connected to the North Bridge chip through the front-end bus (FSB), which in turn exchanges data through the North Bridge chip and memory. The front-end bus is the main channel of the CPU and the external exchange data. Therefore, the data transmission capacity of the front-end bus is large to the computer's overall performance. If there is not enough front-end bus, the strong CPU cannot significantly improve the overall computer overall speed. The maximum bandwidth of data transmission depends on all the widths and transmission frequencies of the data transmitted, that is, the data bandwidth = (bus frequency × data bit width) ÷ 8. At present, the front-end bus frequency can be reached on the PC has several 266MHz, 333MHz, 400MHz, 533MHz, 800MHz. The larger the front-end bus frequency, the greater the data transmission capacity between the CPU and the North Bridge chip, and more fully exerts the CPU Function. The current CPU technology has developed very quickly, and the comparation speed is rapid, while enough front-end bus guarantees enough data to supply to the CPU, the lower front-end bus will not be able to supply sufficient data to the CPU, which limits CPU performance Get played and become a system bottleneck.
The distinction between the frequency and the front end bus frequency: the speed of the front end bus refers to the speed of the CPU and the North Bridge chip bus, and more substantially expressed the speed of the CPU and the external data transmission. The concept of foreign frequency is based on the oscillation speed of digital pulse signals, that is, 100MHz external frequency index pulse signal is shocked by 10,000 times per second, and it has more affected PIC and other buss. Frequency of. The reason why the front-end bus and the outer frequency is easily confused, the main reason is that in the previous period (mainly before Pentium 4 appears and just Pentium 4), the front-end bus frequency is the same. Therefore, it is often called the front-end bus as an outer frequency, and eventually causes such a misunderstanding. With the development of computer technology, people have found that the front-end bus frequency needs higher than the outer frequency, so the QDR (Quad Date Rate) technology is used, or other similar technologies is implemented. The principles of these technologies are similar to the AGP 2x or 4x, which makes the frequency of the front-end bus into the outer frequency, 4 times or even higher, since then, the distal end bus and the cross-frequency difference began to pay attention to it.
