From the sound you shared, it actually sounds like the classic coil whine/electrical interference from a PSU or GPU fan.
I’ve had the same thing with dozens of PSUs (most of them being Seasonics) at low loads, it can start making this buzzing or rattling noise kind of like a faint crackle or whine.

It’s totally normal and not a sign that anything is broken. This happens because the coils or inductors inside the PSU or GPU vibrate, especially when the power draw is low, like during 30 FPS capped cutscenes. When your FPS is higher or uncapped, the load changes and the noise disappears, which is exactly what you observed. It can be a little annoying, but it’s harmless.

edit: If it really drives you crazy, you can try to RMA it. You might get lucky, but most of the time manufacturers don’t accept coil whine as a warranty issue. I’ve RMAed at least three myself because I’m super sensitive to these kinds of noises. I mean, what’s the point of an ultra-silent build if it still makes these sounds? ^^

If you hear this sound it’s already too late. The wire eating ants have infiltrated your case wreaking havoc on your components. I’ve seen this only once before down under (australia). By the time the guy brought his computer in the ants had full control over the desktop creating a sort of sentience.

引用自 East：

If you hear this sound it’s already too late. The wire eating ants have infiltrated your case wreaking havoc on your components. I’ve seen this only once before down under (australia). By the time the guy brought his computer in the ants had full control over the desktop creating a sort of sentience.

Ants, yes, these little suckers can do massive damage even if they are not eating the cable insulation as seen with the Tawny Crazy Ant (Nylanderia fulva), which are highly invasive.

The common black is usually seen around electrical conduits.

It is fascinating when the ants get zapped, the pheromone that they release will attract more ants which leads to a constant cycle.

I doubt it's yellow crazy ants; I think it's just the noises made by the voltage regulators as they react to fluctuations in load on the GPU. When running at a capped framerate, the power draw in the GPU is being pulsed.