Power supply making a buzzing sound

[NiHaoMike]

It's the Cindy Wu circuit, I heard that on the Internets.

The only PSUs I have seen that use Cindy Wu technology (basically a digital inverter for the fan motor) are some ultra high power density rackmount units. Even the 1kW+ ATX units don't run hot enough to require extremely good cooling since power stuff is somewhat more forgiving of high temperatures than delicate logic.

The PFC circuit is the only part of the PSU that deals with the 50/60Hz input. If the power line frequency is 60Hz and the video output is also 60Hz or a multiple (but not exactly), it's possible to get a buzz that cyclically comes and goes. As a test, try setting the refresh rate to something else and see if the noise changes.

If you suspect some high frequency ripple from a voltage regulator getting back to the PSU and causing interactions, you can try adding some clip on ferrites to the cables. Put it around the yellow wires coming off a PCIe or CPU power connector.

 

[Bobnova]

Got a link to any of those? Cause googling it turns up you, and... yeah that's it.
Much like the PSU listed.

 

[NiHaoMike]

It's pretty hard to find much about high power PSUs that small. They're pretty much always custom units going into custom systems. Simply put, they carry a very large price premium and only in small rack servers is that premium justified.

So unless you're using a converted server as a workstation, you probably won't need to worry about that.