How Do I Choose the Best Used CPU?

Generally speaking, overclocking is simply to artificially increase the CPU's FSB or multiplier, so that its operating frequency is greatly improved, that is, CPU overclocking.

Generally speaking. Each CPU has its rated main frequency, FSB and multiplier. The method we use to change the external frequency and multiplier to increase the CPU clock speed is called overclocking. In fact, it simply means changing the operating frequency of the CPU. however. Because overclocking is harmful to the computer. Therefore, it is necessary to understand its technical essentials and clarify the overclocking goals. ^[1]

The first problem to be solved for overclocking is the heat dissipation of the CPU. In addition, individual differences are also the main factors affecting the extreme operating frequency of the CPU. Individual differences

When overclocking, you should grasp a basic principle: first increase the external frequency, and then increase the multiplier. Because the CPU uses the external frequency to communicate with other peripheral devices, and the peripheral settings respond to the CPU at the same speed. If the external frequency is increased, the peripheral equipment has to increase the response speed accordingly. At present, many devices on the computer use the form of PCI bus, and work under the standard operating frequency of 33MHz. The PCI bus frequency is not fixed, but depends on the system bus speed, which is the external frequency. When the external frequency is below 100MHz (66 ~ 83MHz), the motherboard keeps the working frequency of the PCI device at 33 ~ 41.5MHz by two-frequency technology, and when the external frequency is increased to 100 ~ 133MHz, PCI uses three-frequency technology Comes as the operating frequency of the PCI device.

If the external frequency does not use the standard frequencies of 66MHz, 100MHz, or 133MHz, but uses non-standard frequencies such as 75MHz, 83MHz, 105MHz, and 124MHz, the PCl bus can still only use two or three or four. Technology, so that the operating frequency of the PCI system is 37.5MHz, 415MHz and other frequencies. In this way, many components work at non-rated frequencies, and whether they can work normally depends on the quality of the product itself. At this time, whether the hard disk can hold up is the key issue. After the PCI bus frequency is increased, the data exchange speed between the hard disk and the CPU will increase, which will most likely cause abnormal reading and writing, resulting in a crash. Conversely, if all the devices are fine, in a sense, almost all components are overclocked. ^[2]

Increasing the front-end system bus frequency is the most common overclocking method. The front-end system bus is a data channel used to connect the processor and memory. Because the front-end system bus plays a considerable role in the system, the performance improvement brought by increasing the frequency of the front-end system bus is also obvious. And this is not affected by whether the CPU is frequency-locked, and it has the widest range of applications. However, for processors with a high front-side bus frequency, overclocking flexibility is limited.

If the user can adjust the processor's multiplier, then there will be more abundant overclocking options. Intel's processor has completely locked the frequency multiplier, and although AMD processors are also "frequency-locked", the processor's frequency multiplier can be unlocked by some methods. This is also the main reason that AMD processors are very popular in the market. One of the reasons is that without the limitation of frequency doubling adjustment, its performance can be brought to the limit. ^[3]

First of all, if you are very careful and know what to do, then for you overclocking will cause any permanent damage to your computer

CPU overclocking

It's all very difficult. If the system is oversized, it will burn the computer or fail to start. But pushing it to the limit is hard to burn the system.

However, it is still dangerous. The first and most common danger is fever. When you run a computer component above rated parameters, it will generate more heat. Without adequate heat dissipation, the system may overheat. But normal overheating cannot destroy the computer. A situation where a computer is scrapped due to overheating is to try repeatedly to run the computer at a higher temperature than recommended. As far as I said, we should try to keep it below 60 ° C.

But don't worry too much about overheating. There are signs before the system crashes. Random restarts are the most common sign. Overheating is also easily prevented by the use of thermal sensors, which show the temperature at which the system is operating. If you see the temperature is too high, either run the system at a lower speed or use better heat dissipation. Another "danger" of overclocking is that it may reduce the life of the components. When a higher voltage is applied to a component, its life is reduced. A small boost won't cause much impact, but if you plan to overclock significantly, you should pay attention to shortening the life span. However, this is usually not a problem, because anyone overclocking is unlikely to use the same component for four or five years, and it is impossible to say that any component can not last 4-5 years if it is pressurized. Most processors are designed to last up to 10 years, so in the minds of overclockers, it is usually worth the loss of years to gain performance.