picoPSU-160-XT hissing/buzzing

[klatox]

Just recently put together a new build. My aim was to be small and quiet; unfortunately I am experiencing some sort of hissing noise coming from what I believe to be my picoPSU-160-XT. The noise starts right at the moment when the Windows 8 logo appears with the small, rotating white dots. It almost sounds like a light HDD disk activity noise, which is impossible as I have an M.2 SSD. The noise occurs whenever I mouse over something, whenever I scroll, or whenever I move a window around.

I have attempted the following with no success in removing or even reducing the noise.

-Disable Enhanced Intel SpeedStep
-Disable/fumble around with C states (particularly C3/C6 as I read those might be the cause)
-Removing my GPU
-Changing USB ports
-Changing power outlet and power strip
-Changing Windows power settings from Balanced to Performance, etc

Hoping some mad scientist out there can help me out. I've been rummaging through numerous Google search results and forum posts but I'm just totally out of ideas.

[klatox]

I have manage to decrease the noise substantially by adjusting the following BIOS settings (ASUS H97i-Plus):

CPU Integrated VR Efficiency Management: Balanced
Power Current Offset: 12.5%

I also changed Windows Power Plan set to "Power Saver".

I haven't a clue what either of those BIOS settings do, but the noise is reduced. Still there a tiny bit, I may fiddle some more and I'll report back if there are any significant changes.

Cheers.