What is FSB in the CPU

In earlier computers, the speed of synchronization between memory and the motherboard was equal to FSB, in this way, it can be understood that the CPU FSB directly with the memory, to achieve the synchronous running state between the two. For the current computer system, the two can be completely different, but the meaning of FSB still exist, the computer system most of the frequency is based on the FSB, multiplied by a certain number of multiples to achieve, this multiple can be greater than 1, can also be less than 1.

When it comes to processor FSB, it is necessary to mention the two concepts closely related to it: frequency multiplier and the frequency of the CPU clock frequency, multiplier is the frequency and the ratio of FSB. Frequency, FSB, frequency multiplier, its relational type: the clock frequency = FSB x times frequency.

In electronic technology, the pulse signal is a pulse signal which is continuously emitted by a certain voltage amplitude at a certain time interval. We call the interval between the first pulse and the second pulse, and the number of pulses generated in the unit time, such as 1 seconds, is called the frequency. Frequency is the measurement name that describes the number of pulses that occur during periodic cyclic signals including pulse signals in unit time; the standard unit of measurement for frequencies is Hz (khz). The system clock in the computer is a typical pulse signal generator with fairly accurate and stable frequency.

Why is there a clock in the computer system? The computer is a complex data processing system, in which CPU processing data is in accordance with a certain instruction, each execution of instructions, CPU internal operators, registers and controllers must be coordinated with each other, although the length of each execution of instructions, Participating in the operation of the CPU internal unit is more than one, but because all can be synchronized in accordance with the clock pulse synchronization, so the entire system can be coordinated and normal operation. Besides the CPU in the computer, there are storage systems and display systems, and so on, because these systems run with a specific frequency of the clock signal for the standard operation, so in the computer system in addition to CPU frequency and system clock, there are for the ISA and PCI bus and AGP display interface clock, Of course, the frequencies of these clocks are lower than the system clock.

Unit is MHz (megahertz)

The difference between FSB and front-end bus

FSB and front-end bus (FSB) frequencies are easily confused. The speed of the front-end bus refers to the speed of the bus between the CPU and the North Bridge chip, and the speed of the CPU and the external data transmission is more substantial. The concept of FSB is based on the speed of the digital pulse signal oscillation, that is, 100MHz FSB refers to the digital pulse signal at 100 million times per second, it more affect the PCI and other bus frequency. The reason why the front side bus and FSB are easy to confuse the two concepts, the main reason is that in the previous long period of time (mainly in the Pentium 4 before and just appeared Pentium 4 o'clock), the front-end bus frequency and FSB are the same, so often directly called the front-end bus FSB, resulting in such misunderstandings. With the development of computer technology, it is found that the front-end bus frequency needs to be higher than FSB, so the QDR (Quad Date Rate) technology, or other similar technology to achieve this goal. The principles of these technologies are similar to those of 2X or 4X of AGP, which make the frequency of the front-end bus twice times, 4 times times or even higher, since then the difference between the front bus and the FSB has begun to be valued by people.

One CPU default FSB only one, the motherboard must be able to support this FSB. Therefore, when choosing the motherboard and CPU must pay attention to this point, if the two do not match, the system will not work. In addition, the CPU is now a lot of times the frequency has been locked, so overclocking often require a super FSB. FSB changes after the system many other frequencies will also change, in addition to CPU frequency, front-end bus frequency, PCI and other interface frequency, including the frequency of the hard disk interface will change, may cause the system can not run normally. Of course, some motherboards can provide a lock on the frequency of various interfaces.

Set the CPU standard FSB

The current CPU standard FSB only 66MHz, 100MHz, 133MHz (already 200MHz), although the current new motherboards support "soft jumper", that is, through the "BIOS" to set the CPU FSB, but this soft jumper generally can only set a section of non-standard FSB ( Used for overclocking, such as overclocking the standard FSB 100MHz new Celeron to 110MHz. And if the 100MHz FSB new Celeron Overclocking to the standard FSB such as 133MHz, it often depends on the jumper to complete. Note that these are simply used to describe the "FSB jumper" function, the most basic function of the jumper is "for different FSB CPU, on the motherboard correctly set its FSB, make it work."