I have experienced mild to heavy coil whine around on the keyboard panel near the power jack. After running some search, I noticed that lots of similar cases happened to XPS 13 and it's somewhat related to the TurboBoost on CPU.
When I turned off the TurboBoot in BIOS, the coil whine did become basically inaudible. But it induces a performance hit which I'm not willing to take.
Can Dell do a BIOS update to solve this as you did with the XPS series?