Bad news. My previous RX 560 purchase was proven to be wrong. My old R9 nano is not faulty, and the fault was a WiFi card shipped with my motherboard. 15% restocking fee down the drain.
Lesson learned: never buy cheap motherboards from AsRock. I knew $200 for an X99 mobo with WiFi and USB3.1 can't be good, but anyway. It's indeed very stupid to put a $200 mobo in a multi-thousand-dollar dream setup.
Arrived today is a Mediasonic external HDD raid box which I'm using in my NAS setup. I no longer want my HDDs to be in my main computer chassis, so I need to find a place to plug them into.
I did 2 modifications on the enclosure, first by adding a DC/DC module in fan cable to step down the noise, then by adding another DC/DC module to convert 19V to 12V, so I can tap power from my Intel NUC power brick to power my HDD enclosure. The NUC PSU is a 65W unit, and the NUC will never suck more than 25W from it.
Those Amazon $10/4-pack DC/DC modules are actually quite efficient -- they run very cold, not even warm to touch, while stepping down 19V to 12V, ~1.5A, without any thermal solution, wrapped in electrical tape.