The relationship between computing power and frequency

1. 1. Main frequency: the main frequency is also called clock frequency, the unit is MHz, which is used to indicate the CPU operation speed. The main frequency is determined by external frequency and frequency doubling, and its calculation formula is main frequency = external frequency * frequency doubling. External frequency is the working frequency of system bus; 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 Intel Pentium4 3.06GHz processor is 133 and the frequency multiplier is 23, then the main frequency = 133 * 23 = 3.06GHz

2. External frequency: the external frequency is the reference frequency of CPU, and the unit is MHz. External frequency is the speed of synchronous operation between CPU and motherboard. In most computer systems, external frequency is also the speed of synchronous operation between memory and motherboard. In this way, it can be understood that the external frequency of CPU is directly connected with memory to realize the synchronous operation between them

3. Front end bus: the frequency of front-end bus directly affects the speed of data exchange between CPU and memory. Because the maximum bandwidth of data transmission depends on the width and transmission frequency of all data transmitted at the same time, that is, the amount of data transmission = (bus frequency * data bandwidth) / 8. The difference between external frequency and front-end bus frequency: the speed of front-end bus refers to the speed of data transmission, and external frequency refers to the speed of synchronous operation between CPU and motherboard. For example, 100MHz external frequency refers to 10 million oscillations of digital pulse signal per second, while 100MHz front-end bus refers to the amount of data transmission acceptable to CPU per second, which is 100MHz * 64bit / (8byte / bit) = 800MB / s

4. Frequency multiplication coefficient: frequency multiplication coefficient refers to the relative proportional relationship between CPU main frequency and external frequency. Under the same external frequency, the higher the frequency doubling, the higher the CPU frequency. But in fact, under the premise of the same external frequency, the CPU with high frequency doubling has little significance. This is because the speed of data transmission between CPU and system is limited. The CPU that blindly pursues high frequency multiplication and obtains high dominant frequency will appear obvious "bottleneck" effect - the limit speed of data obtained by CPU from system cannot meet the speed of CPU operation< Memory bus speed: the data processed by CPU comes from memory, and the main memory is memory. Generally, the data on the external memory (disk or various storage media) should be processed by the CPU through the memory. So the speed of memory bus between CPU and memory is very important to the performance of the whole system. Because the running speed between memory and CPU will be more or less different, so there is a secondary cache to coordinate the difference between them, and the memory bus speed refers to the communication speed between CPU and secondary 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 expansion bus is the bridge between CPU and these external devices
the above is in the textbook, which can ensure the correctness
to play overclocking, first download Everest, which can test the feasibility data of your computer's overclocking
computer's overclocking is to increase the working frequency of CPU, graphics card and other hardware by artificial means, so that they can work stably at a frequency higher than their rated frequency. Taking the Intel P4C 2.4GHz CPU as an example, its rated working frequency is 2.4GHz. If the working frequency is increased to 2.6GHz, the system can still operate stably, then the overclocking is successful

the main purpose of CPU overclocking is to improve the working frequency of CPU, that is, the main frequency of CPU. The main frequency of CPU is the proct of external frequency and multiple frequency. For example, if the external frequency of a CPU is 100MHz and the frequency multiplier is 8.5, its dominant frequency can be calculated as external frequency × Frequency doubling = 100MHz × 8.5 = 850MHz

the main frequency of CPU can be improved by changing the frequency doubling or external frequency of CPU. But if you are using Intel CPU, you can ignore the frequency doubling, because Intel CPU uses a special manufacturing process to prevent the modification of frequency doubling. AMD CPU can modify frequency doubling, but the improvement of CPU performance is not as good as external frequency

the speed of external frequency is usually closely related to the speed of front-end bus and memory. Therefore, when you improve the CPU external frequency, the performance of CPU, system and memory also improves

there are two main ways of CPU overclocking:

one is hardware setting, the other is software setting. Hardware settings are commonly used, which are divided into jumper settings and BIOS settings<

1. Jumper setting overclocking
most early mainboards used jumper or dip switch setting to overclocking. Near these jumpers and dip switches, some tables are often printed on the motherboard, recording the functions defined by the combination of jumpers and dip switches. In the off state, you can set the frequency according to the table. After rebooting, if the computer starts up normally and runs stably, it means that our overclocking is successful
for example, an Intel 845d chipset motherboard used with Celeron 1.7GHz adopts the mode of jumper overclocking. Below the inctance coil, we can see the description table of jumper. When the jumper is set to 1-2 mode, the external frequency is 100MHz, and when it is changed to 2-3 mode, the external frequency is increased to 133MHz. The default external frequency of Celeron's 1.7GHz is 100MHz. As long as we upgrade the external frequency to 133MHz, the original Celeron's 1.7GHz will work at 2.2GHz, isn't it very simple:)

another via kt266 chipset motherboard used with AMD CPU uses dip switch setting method to set CPU frequency doubling. Most of AMD's frequency doubling is not locked, so it can be modified to carry out overclocking. This is a five group dip switch, which can be combined into more than ten modes through different on-off states of each serial number switch. A description table is printed on the top right of the dip switch to illustrate the changes of different frequencies caused by different combinations of DIP switches

for example, when we overclock an AMD 1800 +, we should first know that the dominant frequency of Athlon XP 1800 + is equal to 133MHz external frequency × 5 times. As long as we increase the frequency doubling to 12.5, the CPU dominant frequency will be 133MHz × 12.5 ≈ 1.6GHz, equivalent to Athlon XP 2000 +. If we increase the frequency doubling to 13.5, the main frequency of CPU will be 1.8GHz, and the over frequency of Athlon XP 1800 + will become Athlon xp2200 +. The simple operation will greatly improve the performance, which is very interesting<

2. BIOS setting overclocking
now mainstream mainboards basically give up jumper setting and dip switch setting mode, change CPU frequency doubling or external frequency, and use more convenient BIOS setting

for example, softmenu III of abit and powerbios of epox belong to the mode of BIOS overclocking. In CPU parameter setting, you can set the frequency doubling and external frequency of CPU. If the computer can't start normally after overclocking, just shut down and press ins or home key, restart, the computer will automatically return to the default working state of CPU, so it's better to overclock in BIOS

here, the combination of nf7 motherboard and Athlon XP 1800 + CPU is used to realize the overclocking. At present, there are two main brands of BIOS in the market, one is phoenix award BIOS, the other is AMI BIOS, here is award BIOS as an example

first start the computer and press del to enter the BIOS setting interface of the motherboard. Select soft menu III setup from BIOS, which is the softmenu overclocking function of upgrade motherboard

after entering this function, we can see that the system automatically identifies the CPU as 1800 +. We need to enter here to change the default recognized model to user define mode. After setting to manual mode, the original gray non optional CPU external frequency and frequency doubling are now in the optional state

if you need to use the enhanced external frequency to overclock, enter here at external clock: 133MHz. There are many external frequencies to adjust. You can adjust it to 150MHz or higher. Because the increase of external frequency will increase the frequency of system bus and affect the stability of other devices, the method of locking PCI frequency must be adopted

multiplier factor is the place to adjust the frequency doubling of CPU. After entering the options area, you can select the frequency doubling according to the actual situation of CPU, such as 12.5, 13.5 or higher

rookie: if the system can't start normally or work unsteadily after CPU overclocking, I heard that it can be solved by increasing the core voltage of CPU. Is that reasonable< A Meng: Yes. Because CPU overclocking, power consumption will increase. If the supply current remains unchanged, some CPUs will not work normally and stably e to insufficient power consumption. After increasing the voltage, the CPU gets more power, which makes the overclocking easier to be successful and stable

the core voltage of CPU can be set and adjusted in BIOS (as shown in Figure 7). Under normal circumstances, you can select the default state. If the system is unstable after the CPU overclocking, you can add voltage to the CPU core. But the side effect of voltage is very big. Firstly, the heat of CPU will increase. Secondly, if the voltage is too high, it is easy to burn the CPU. So you must be careful when adding voltage. Generally, you can add it in steps of 0.025v, 0.05v or 0.1V

3. Using software to achieve overclocking
as the name suggests, is to achieve overclocking through software. This kind of overclocking is more simple. Its characteristic is that the set frequency will recover after shutting down or restarting the computer. If rookies do not dare to achieve hardware setting overclocking at one time, they can first test the overclocking effect with software overclocking. The most common overclocking software includes softfsb and software developed by motherboard manufacturers. They all have the same principle, which is to control the frequency of the clock generator to achieve the purpose of overclocking

softfsb is a general software, which can support dozens of clock generators. As long as you select the clock generator model used on the motherboard, click Get FSB to get the control right of the clock generator, and then you can set the overclocking through the frequency lever. After selection, press save to let the CPU start working according to the newly set frequency. However, the disadvantage of software overclocking is that when the CPU can't bear the frequency you set, it will cause a crash or system crash at the moment you click save<

Secret skills of CPU overclocking:
1. CPU overclocking is related to the "constitution" of CPU itself
many friends say that their CPU is still unstable after overclocking, which is the "constitution" problem. For the same type of CPU, the super ability of different proction cycles is different, which can be reflected from the processor number< The CPU with low frequency doubling is better than the CPU with low frequency doubling
as we all know, improving the external frequency of CPU is faster than improving the frequency doubling performance of CPU. If the CPU with frequency doubling is not locked, the experts will use the method of increasing the external frequency and recing the frequency doubling to achieve better results, so that the CPU with low frequency doubling has inherent advantages. Such as amd Athlon xp1700 + / 1800 + and Intel Celeron 2.0GHz<

3. The more advanced the manufacturing process, the better. The more advanced the manufacturing process is, the higher the frequency can be achieved when the CPU is over frequency. For example, Intel's newly launched Intel Celeron D processor, which has won wide attention, adopts 90 nm manufacturing process and Prescott core. Some netizens have surpassed the 2.53GHz celeron d to 4.4gh

2. Frequency is the number of events in n experiments, and frequency is the proportion of the number of events in the total number n. I.e. frequency = frequency / n

3. Wavenumber = frequency / speed of light, 1MHz = 1 / 30000 wavenumber

4. Frequency and return period are both used to indicate the possible opportunities of certain flood, rainstorm or water level, which are called "frequency". The frequency is expressed in percentage and the return period is generally expressed in years
for example, in a certain river, the peak discharge of 7000 m3 / s may occur once in 50 years, the frequency is 2%, and the return period is 50 years. It is also called the flood with a return period of 50 years. The frequency is calculated based on the results of many years of observation in a certain place< In general, there are three methods to measure frequency: passive frequency measurement, active frequency measurement and electronic counting. Passive frequency measurement method (which can also be divided into resonance method and bridge method) is often used in frequency rough measurement, and the accuracy is about 1%
the active comparison method can be divided into beat frequency method and difference frequency method. The former uses the linear superposition of two signals to proce beat frequency phenomenon, and then uses the detection of zero beat phenomenon to measure frequency. It is commonly used in low-frequency measurement, and the error is within a few tenths of Hz
the latter uses the superposition of two nonlinear signals to proce the difference frequency phenomenon, and then detects the zero difference phenomenon to measure the frequency, which is often used in high-frequency measurement, and the error is less than 10% ± 20
Hz
source of reference: Network - frequency and recurrence rate

5. Bandwidth 50K refers to the frequency range. Frequency and spectrum are two completely different concepts. The difference is that the spectrum is a function of frequency. Specifically, spectrum refers to the characteristics (large or small) of a signal at different frequencies (such as 5Hz and 10Hz). For example, frequency is like spring, summer, autumn and winter, while frequency spectrum refers to the weather conditions in the four seasons of spring, summer, autumn and winter.

6.

The relationship between period and frequency: F = 1 / T Where f is the frequency and t is the period)

Frequency is the number of times that a substance changes periodically in 1 s, which is often expressed as f. In order to commemorate the contribution of German physicist Hertz, people named the unit of frequency as Hertz, abbreviated as "Hertz", and the symbol is Hz

period, the time that an object moves back and forth or the physical quantity changes repeatedly. The time taken by an object or physical quantity (such as alternating current, voltage, etc.) to complete a vibration (or oscillation)

in all kinds of periodic motion or periodic change, the object or physical quantity changes from any state, and always returns to the original state after a period or an integral multiple of the period. Period is also a physical quantity to describe the speed of uniform circular motion. Long period means slow motion, short period means fast motion

The relationship between frequency and period is f = 1 / T, which is inversely proportional

extended data:

the methods of frequency measurement are generally divided into passive frequency measurement method, active frequency measurement method and electronic counting method

The passive frequency measurement method (which can also be divided into resonance method and bridge method) is often used in frequency rough measurement, and the accuracy is about 1%

2. The active comparison method can be divided into beat frequency method and difference frequency method. The former uses the linear superposition of two signals to proce beat frequency phenomenon, and then uses the detection of zero beat phenomenon to measure frequency. It is commonly used in low-frequency measurement, and the error is in a few zero Hz

However, the electronic counting method is mainly controlled by single chip microcomputer. Because of the strong control and operation function of the single chip microcomputer, the electronic counting method has wide frequency range, high precision and easy realization

7. Wave number is usually expressed as K, k = 2 π/λ,λ It's the wavelength, not the same as the frequency, f = 1 / T= ω/( two π), T is the period, ω It's angular velocity. As for its Fourier transform, I'm not sure. I'm not an optical major. You can check it in the library. It should be very easy to check

8. Hertz is the unit term of frequency. For example, the frequency of 220 V power supply is 50-60 Hz
the frequency of sound that can be heard by human ears is 20-20000 Hz
the bass frequency is 20-200hz and the midrange frequency is 300-3000Hz. The treble is 3000-20000 Hz

9.

The vertical axis represents the frequency / group distance, that is, the height of the rectangle, and the line segment on the horizontal axis with two adjacent points as the end points is the bottom of the rectangle. The area of the rectangle represents the frequency, and the area of each rectangle is a small rectangle. The area of the rectangle = group distance * (frequency / group distance) = frequency

when the number of repeated tests n increases graally, the frequency FN (a) presents stability and graally stabilizes to a constant, which is the probability of event A. this "frequency stability" is also known as the statistical regularity

extended data:

the relative frequency M / N of random events in n trials. In general physics, frequency refers to the number of vibrations per second, which can be random or deterministic

The probability p (a) of the occurrence of

random event a is a measure of the probability of the occurrence of the event. Its value is between 0 and 1. Under certain conditions, if event a is impossible, then p (a) = 0; If event a must occur, then p (a) = 1. With the increase of the number of tests n, the probability that the frequency is close to the probability is greater

10. The physical meaning of frequency is the number of turns in one second (or the number of repetitions of an identical action)
F = 1 / T
isn't the number of turns in one second divided by the time of one turn t