PSU Whines But Only After Windows Boots

[Collider]

So I got a handful of EVGA 450 PSU's for a build I'm doing.
https://www.bhphotovideo.com/c/product/1360176-REG/evga_100_bt_0450_k1_450bt_450w_80_plus.html

The problem is that all of them emit a coil whining noise, BUT only after Windows boots. Normally I would assume that Windows puts on a higher load on the PSU, but the load is actually much higher during boot ~200W and when in Windows only ~100. There is no whining noise during boot, only after Windows starts up.

I have 6 of them, tested 3 and all 3 have the same problem. Obviously I want to RMA these but I just find it weird that the whining noise comes only in Windows, curious as to why?

Is there anything I should try, or don't waste time and just RMA them?

 

[VirtualLarry]

Just set your Power Plan to High Performance, and / or disable "C states" in BIOS.

It's probably the default power-saving in Windows, that enables and disables CPU cores thousands of times a second, causing audible noise in that freq. range.

 

[Collider]

Turns out 3 out of 6 have this issue. Very audible whining noise at low loads. Decided to return all of them and get a higher level PSU model.

 

[VirtualLarry]

Did you try my suggestion at all? I'm curious if it made the whining go away.