Long story short my HP Z420 has a coil whine issue...
The noise is coming from some coils directly beside the CPU however don't want to pop off the CPU cooler to find out what particular coil is making this noise.
I've heard that putting hot glue over them can dampen the noise but this seems like a bad idea in my books. It is related to load - if I put my PC into "Power Saving" mode most of the noise goes.
Any ideas? It is incredibly loud.