Weird squeeky sound?

[Replicon]

This may sound like a troubleshooting thing at first, but I'm really more curious on what this is...


On the majority of computers I've used, I find there's a funny squeeky sound that can be generated under certain conditions. Usually, it's when dragging the mouse while the CPU is doing lots of work.

For example, if I sometimes in Excel, if I have a cell with "6.3.1.1", and I drag the corner down to generate "6.3.1.2" and so on, while I drag, I hear a funny squeeky sound.

If I had to take a guess, I would guess it's the hard drive (or maybe some weird component that whines when the cpu draws a lot of power?)... but what causes this? I've seen this in many a computer, so it sounds like it might be normal behaviour. I hope someone knows what I'm talking about 😛.

 

[icarus4586]

I've heard it too. It puzzled me, because it sounded like it was coming from the CPU, but I couldn't think of why the CPU would be making a noise. I read an article about Apple PowerMac power supplies making a "chirping" noise when the CPU changed power states, and I believe it's the same thing happening in my case. What happens is that, as the power draw changes quickly and dramatically (like when the CPU throttles up and kicks up its voltage to do some heavy lifting) it can actually make some of the components inside the power supply vibrate a very small bit. I'm not an electrical engineer, so I don't know the specifics for why it happens, but I think that's what's happening in your case too.

 

[Jeff7]

I had a similar issue with an old laptop and a Seasonic PSU, though the latter only seems to make the noise when plugged into my campus' power grid.

 

[patentman]

Likely its just noise that is being picked up by the soundcard under high load. I'm thinking something similar to the whining noise you can get if you don't have clean connections to an amplified speaker in an audio system.

 

[bobsmith1492]

It's probably from the power supply system; they use switching supplies with inductors that can vibrate under stress.

 

[Rubycon]

Originally posted by: bobsmith1492
It's probably from the power supply system; they use switching supplies with inductors that can vibrate under stress.

That's exactly what it is. Inductor sing can often produce sounds rich in harmonics from the fundamental exciter which may or may not be in the audible range of human hearing. What's even stranger is the events that actually produce these noises. Video cards and VRM components near the processor are often the most guilty parts.