This article was reprinted with permission from Superpower.com.
In summer, the role of the radiator is more important. Whether it is the CPU, the graphics card or the chassis, the power supplies all need cooling fans. How to control the fan's noise and performance is also a big deal.
This problem can determine that some fans sell hundreds of dollars. Some fans can only sell tens of dollars or even a few bucks. The former tends to enter the high play house. The latter can only enter the homes of ordinary people. It's hard to avoid people's feelings.
Today to talk about the fan interface, many people still can not distinguish between fan 2 pin, 3 pin and 4 pin difference.
The type of cooling fan - 2 needles, 3 needles, 4 needles
There are many kinds of cooling fan classification methods, there are DC DC, AC AC points, can also be divided into brush, brushless, there are ball bearings, oil bearing points, we talk about here is the cooling fan power cord interface.
In simple terms, it can be divided into 2pins, 3pins and 4pins. Let's look at them one by one.
Cooling fan's 2-pin, 3-pin and 4-pin (Photo by togell)
2-pin fan: Simple but rough, but not speed
2-pin cooling fan means It has only red and black power lines, a ground, a power supply, a simple structure, but the function is also very few, can not be measured speed, want to speed the need to use other programs.
In addition to the 2-pin fan mentioned above, There is also a D-type power connector fan, which is a large 4pin fan interface. Here is also categorized as a 2-pin fan. The representative fan is the cool black whirlwind series.
Cool black whirlwind big 4pin interface fan (picture from Taobao shop)
This kind of fan also has no variable speed function, and the power supply is 12V, with a large 4pin interface is to get better performance (more power). Cool cold black whirlwind speed is 1200RPM, air volume is 44.72CFM.
Here I think that because of the poor thermal environment in the past few years, I bought a few 1,500 RPM violent fans with a hot head. I also used a large 4-pin interface. The air volume was really strong, but the noise could not stand. I gave up after using it twice. .
At present, the 2-pin fan has not withdrawn from the stage. There are still many applications in different occasions. However, for DIY players, the 2-pin fan can no longer meet the requirements in terms of variable speed, etc. 3-pin, 4-frame fan is More suitable choice.
3-pin fan: VC voltage regulation, poor flexibility
The problem that the 2-pin fan can't adjust the speed is becoming more and more serious in the society because people don't always need the fan to run at full speed. When the temperature is not high, lowering the fan speed can bring lower noise. The demand for silence is increasing. So there is a 3-speed fan interface with adjustable speed.
The 3-pin fan connector adds a yellow line (also partly black and yellow-green) to the original red-black connection. It is mainly responsible for speed measurement. Through its motherboard, it can detect whether the fan is rotating or not.
However, the speed of the 3-pin fan is through Adjust the fan voltage To achieve, first of all to adjust the speed is still not flexible enough, temperature detection from the motherboard, can not reflect the CPU status information in real time, but also requires the motherboard BIOS to set various parameters, it can not adjust the speed depends on the motherboard support or not.
More importantly, different fans have different starting voltages. The speed regulation of the voltage is not linear, and controlling the speed through the voltage may cause the voltage required for the fan to reach the low voltage, causing the fan to stall.
4-pin fan: More flexible and smarter speed control
From 2 pins to 3 pins, the problem of fan speed regulation has not been completely solved, so in the LGA775 era, Intel's joint manufacturer introduced a new PWM speed regulation specification, and the cooling fan has become 4 pins. On the basis of the 3-pin one more PWM line (pulse width modulation).
The 4-pin fan's interface color is also not fixed. Commonly there are the following two:
4-pin fan interface color and interface definition
The additional PWM line is the use of PWM mechanism to adjust the fan speed, and the fan voltage is constant, to avoid the control of the voltage to a series of shortcomings.
In addition, the PWM pulse signal can output different Duty Cycles. The duty cycle between 0-100% can adjust different fan speeds. Therefore, accurate and flexible control can be achieved, and the PWM fan can do To not rely on the motherboard BIOS, easy to use.
The main radiator fan is PWM type
Speaking of PWM speed regulation, there are actually many specific technical classifications. PWM also has low-speed PWM and high-speed PWM. There is a wider range of low-frequency PWM measurement speed, but there will be fan commutation noise. Frequency PWM overall performance will be better.
3-pin, 4-pin fan, interface interleaving and precautions
Sometimes, even if the fan has 4-pin PWM control, but still can't control the speed intelligently on the motherboard, this problem may be related to the motherboard, because the 4-pin interface on the motherboard may not be PWM-controlled. It may also be a voltage controlled speed.
The 4-pin connector of some motherboards is not necessarily PWM
The owl mentioned this issue in the official FAQ. This depends on the description of the motherboard manufacturer. If the NC, VCC or other words are mentioned, it means that it does not support the PWM speed regulation, which is achieved by reducing the voltage.
Another problem is the mixed insertion of 3-pin and 4-pin fan. Since there are 3 pins in the two are the same, it can be mixed. Of course, the 4-pin fan will lose the PWM speed control function by inserting the 3-pin interface. , The 3-pin fan will not automatically get the PWM speed adjustment function when it is inserted into the 4-pin connector.
to sum up:
The 2-pin, 3-pin, and 4-pin cooling fans are commonplace issues. Currently, 2-pin fans are rare in daily use, with 3 pins and 4 pins.
From the use of experience, the choice of 4-pin fan with PWM function, the motherboard is the first choice, Fortunately, this is not a problem now, Most of the motherboard and CPU fan with fan 4-pin PWM.
Picture from Taobao shop
In fact, we talk about the 2-4 pin just the difference in quantity, specific to the interface, it also exists in different types. In this regard, many shops on Taobao is actually very clear, we see how many can recognize.
