msi z490 tomahawk

Hi guys, I have a Z490 Tomahawk and 10850K, I've been playing around with undervolting in the form of a negative vcore offset. Some background, I don't use turbo boost because I prefer a cooler and quieter machine. I manually set the CPU multiplier to 45. Today I've been experimenting with...

I spent using this pc over 6 months with no problems regard weird noises, and then next day powered up the machine I hear this noise all time with no stop if idle, when I am playing gaming or doing heavy work, lets say playing bf4 after like 10m I started hearing the noise keep fading, sometimes...