What is the cause of the high frequency sound of the PC graphics card? (Coil shaking sound?)
Investigate what I experienced and what caused the problem.
Recently, I have experienced the following problems, and I have analyzed and solved the cause.
➡ I replaced the graphic and turned the high-end game or benchmark, and it caused noise.
➡ Attempts to inquire about product replacement with an initial defect because it is considered to be a high-frequency sound known on the market.
➡ When the company found out what the cause was, it was inevitable because it was a coil shaking sound or because it was a household ground problem, so it was recommended to use an electromagnetic wave blocking multi-tap.
➡ As I looked into similar phenomena more on the Internet, there were many opinions that it was the same even if I bought a multi-tap.
➡ Some people say that the sound disappeared when the power supply was replaced with a large capacity (more than 1 kW).
➡ However, there are many rumors that large construction and expenditure are doing well with the current power, so I try to turn a blind eye.
A more detailed explanation of the problem.
1. The main culprit of sound. Coil?
The 20 Hz to 20 kHz of the audible frequency range is said to be an area that humans can hear.
Coil tremors are said to be the most likely, but it has been a long time since graphic cards have overcome them.
Even if I can't do the days when the coil was shaking, I think it was almost 10 years ago.
First of all, the 12V VRM circuit for GPU power supply switches from hundreds of kHz to several MHz, and the coil (inductor) used for each channel is a high current inductor with a frequency of 0.22uH corresponding to 5 MHz, and it is considered to have little noise as it was released with a shield or mold type.
Note here that the VRM switching frequency, hundreds of kHz to several MHz frequency.
Even if the coil shakes, it already exceeds the audible frequency.
I think the person who can hear this is a superpower.
2. Type of sound. High frequency? Is it high frequency?
Even in the audible frequency band, there are sometimes very unpleasant and annoying high-frequency sounds such as tinnitus. This is a frequency that is almost over 10 kHz. Some people cannot hear it due to hearing aging.
This is not the sound I hear on my graphics card in question.
It's a so-called trembling sound, a low-tone "stabbing" sound that anyone can hear, unlike tinnitus. It's like a frequency distributed in the range of about hundreds of Hz to 1 kHz.
3. 12V Power Department Review.
It's very important. The higher the 12V power supply, the more current it needs.
It has been confirmed that the voltage of 12V, the main power source, drops when driving high-specification graphics these days, and the current waveform is not constant like PWM. Waveforms that repeat current drops and rises at regular cycles are mainly observed. Of course, my performance won't come out, right?
Then, why does that waveform come out?
Where the maximum output current of the power supply exceeds the maximum output current, the over current protection function called OCP is to protect the circuit and load, and most of them are automatically recovered and operated normally. There are modes called Foldback, Hiccup, and Shutdown (Latch), of which Foldback reduces the output current by almost half and outputs it, Hiccup repeats turning it off and on, and shutdown is said to be a mode of turning it off and down at all.
4. What's the cause of the sound?
The 12V power input unit uses an MLCC called a chip capacitor to remove high-frequency noise. This is widely used as a too basic and universal method of circuit design.
MLCC is a cap from a long time ago that secures capacitance by stacking dielectric and metal plates in multiple layers. In other words, it is also called piezoelectric element.
This piezoelectric structure makes a sound when an alternating current component (such as sound waves) is applied to a metal plate with a dielectric in between. The product using this serves as a buzzer that makes a "tiriri" sound to the front door lock or various devices.
If you search MLCC Vibration on Google, you will find many solutions to problems and solutions from the world's leading electronics companies.
Conclusion
To tell you a realistic conclusion that can be solved by the high frequency sound (coil shaking sound), the power should be replaced (upgraded higher than expected).