How can the computer be loud when it is hot?

Everyone wants to use the computer in a quiet environment. Excessive computer noise not only hinders navigation in the multimedia world, but also undermines the interest in using computers. In the past, my CPU was cryix 6X86, which was famous for its calorific value. The power of the cooling fan is as high as 2 1W (using current of 0. 18A), so the noise of the cooling fan is very high. In addition, when my hard disk reads and writes files, it always makes harsh noise (the sound of head seeking), which is really unbearable. It was this "painful" experience that made me interested in computer noise reduction. I have gained something from my study and exploration. I intend to share my experience and lessons with you through this article.

There are two main sources of noise from desktop computers:

1, CPU fan and regulated power supply fan.

With the development of PC technology, the chip integration and power consumption gradually increase, and the number of heat sources is also increasing. You need to use a high-power cooling fan to work stably. The increase of the number of fans and the acceleration of rotating speed will inevitably increase the noise caused by airflow and mechanical friction.

2, hard disk high-speed rotating motor and seek head.

At present, the speed of hard disk motor has been increased to 7200 rpm or even 10000 rpm, which greatly shortens the seek time. While improving the performance, the noise generated by mechanical friction is also increasing.

At present, there are many methods to reduce these two kinds of noise, but most of them are not obvious or practical, mainly including:

1, the common method to reduce the noise of CPU fan is to reduce the fan speed.

Transform the power interface to reduce the working voltage of the fan from 12V to 5V, thus reducing the speed of the fan; Secondly, because the power of the fan is proportional to the noise, high-power fans generally use a current of more than 0. 15A, so they can switch to low-power fans with a working current of less than 0. 12A. The above methods can indeed reduce the noise to a certain extent, but you must risk that the CPU will overheat in hot summer, which may shorten its life or be burned down, making people uneasy to use it. In addition, it is also a noise reduction method to add lubricants such as clock oil and vaseline to the fan from time to time to reduce friction. However, this method is effective in the short term because oily substances are easy to absorb dust and impurities. But over time, the accumulated dust and impurities will increase the friction, and then the noise will be even louder.

2. Reducing the noise of the power supply fan is similar to reducing the noise of the CPU fan, that is, starting with reducing the fan speed. Using temperature-controlled power supplies with thermistors (such as Hangjia LW-7250 and LW-8250), when the internal temperature of the power supply box is low, the fan runs at a low speed, and when the internal temperature of the power supply box rises, the fan speed will automatically increase. The disadvantage of this method is that the temperature control power supply itself is expensive and cannot provide the powerful heat dissipation capacity required by ordinary overclocking.

3. Methods to reduce hard disk noise.

The common method is to set the automatic sleep function of the hard disk, such as selecting the appropriate hard disk power-off time through the BIOS power management setting option, or setting the appropriate hard disk power-off time in the WINDOWS power management option. If the system does not access the hard disk within the selected time, the hard disk motor will automatically stop running.

Generally speaking, this method is not practical. First of all, it can't eliminate the harsh noise caused by head seek when reading and writing files continuously. Secondly, the hard disk is powered on and the number of times the head starts and stops is limited. In the early days, the trouble-free working time of hard disk was about 300,000 hours, while the number of times the head started and stopped was only1-30,000 times. The upper limit of the latest IDE hard disk head started and stopped was only 654.38+10,000 times. Frequent hard disk hibernation not only affects the continuous working speed of the system, but also shortens the physical life of the hard disk.

4. The latest overall design.

Because there are too many noise sources in the computer, it is difficult to completely solve them by one or two methods, so some people have put forward the design of "cabinet-type" and "split-type" computers, that is, putting the main chassis of the computer in the cabinet with the front panel closed or in another room to make it "invisible, inaudible and trouble-free". Theoretically, this method works best, but you must have a long signal line, and it is not convenient for you to switch CDs or floppy disks frequently.

And I think computer noise is closely related to "* * * vibration", which mainly comes from three aspects:

1, "* * * vibration" of CPU fan and heat sink.

Usually, a high-speed rotating fan will hit the heat sink at high frequency. If the fan and heat sink are stable and suitable, the vibration and noise caused by collision can be greatly reduced. For example, holding a high-speed rotating CPU fan in your hand is far less noisy than fixing it on a heat sink, because a soft hand will absorb a lot of vibration. According to this principle, adding 1-2 mm thick soft gasket (such as leather, rubber, etc.) between the four corners of the fan and the contact surface of the heat sink can effectively reduce the noise caused by the vibration of the fan and the heat sink.

2. There is "* * * * vibration" between the high-speed rotating hard disk and the chassis hard disk bracket.

Usually, the "click" sound when reading or writing a hard disk is generated by head seeking. The seek speed of the magnetic head in high-speed hard disk is fast, and its center of gravity is unstable due to high-speed rotation. If the chassis hard disk bracket is too thin or the screws are not fixed properly, the hard disk will collide with the chassis hard disk bracket, which will amplify the sound of head seeking and make it more penetrating.

Through many experiments, I found a very effective way to reduce this noise. The steps are as follows: First, remove the hard disk from the 3.5-inch hard disk shelf, and then horizontally place it in the center of the lowest layer of the 5.5-inch hard disk shelf. Don't touch metal objects around the hard disk. Put a foam pad under the hard disk body (such as foam in the motherboard packaging box), and then simply fix the hard disk in the bracket with transparent tape to prevent it from moving back and forth. Because the vibration of the hard disk itself is absorbed by the foam pad, the harsh "giggle" sound emitted by the hard disk when reading and writing will be greatly reduced. This method has been successfully tried on several computers and the noise reduction effect is very good.

In addition, there are other noise reduction methods, here to introduce to you:

1, the use of semiconductor radiator, which completely eliminates the noise and has good heat dissipation effect. Its disadvantages are relatively expensive, high power consumption and easy to be damaged. The condensation phenomenon on its surface may endanger the safety of the circuit board, but from the perspective of future development, it may eventually replace the cooling fan.

2. Use a drawer-type hard disk box. Hard disk box can play a certain sound insulation role, and it has its own cooling device, so you don't have to worry about the ventilation problem of hard disk, but the price is still relatively expensive (100-200 yuan).

3. Because the thin iron case is easy to vibrate, spending tens of dollars to buy a thick steel case can make your computer quieter when working.