Question AuraSync Compatible yet 3-pin RGB on cooler, 4-pin on motherboard?

stlsailor

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Sep 25, 2017
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I am doing a build with a ASUS Maximus XII Hero Wifi LGA 1200 and also I have bought, but not opened, a Fractal Design Celsius+ S28 cooler. I don't care much about RGB, but who knows about the future, and if something should work, I want it to be able to work should I ever change my mind. How can the cooler be AuraSync compatible when I discovered yesterday from the FD website that it has a 3-pin RGB connector which apparently runs on a different voltage and is not compatible with the 4-pin RGB on the motherboard? It seems like the RGB won't work at all if I understand FD's website correctly. This is something I haven't seen in the specs, and both PCPartPicker and NewEgg said it was compatible. So perhaps there's something I don't understand.

RGB is new since my last build, so I don't really know much about it. Just trying to decide if I should exchange the cooler, or if I misunderstand and the RGB somehow works differently.
 

stlsailor

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Sep 25, 2017
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Well, it seems to always happen. No matter how many hours I spend researching before I post, not long after I seem to run across a clue to the answer somewhere. So, for anyone else puzzling over this, here is what I think the situation is.

First the ASUS motherboard seems to have two aRGB headers but they are marked ADD Gen2. I didn't pay much attention to them because I was looking for RGB or aRGB headers and with USB's crazy naming scheme everybody and there brother is called Gen 1 or Gen 2. It turns out, however, that ADD Gen2 is simply a cleverly disguised alias for addressable RGB.

The other thing about these headers is that the FD website made a big point about how their 3-pin connectors wouldn't work with 4-pin headers. And these were apparently 4-pin headers. But, on closer examination, they were in fact 3-pin that looked like a 4-pin until you noticed that one of the interior pins was missing. Finally an examination with a magnifying glass turned up a very tiny +5V on the motherboard, almost unseeable.

So it turns out there is no issue, merely obfuscation that cost me a few hours.

And so, when I open the cooler box as I'm ready to install, I expect I will find there a four slot 3-pin connector, probably with one of the slots blocked to prevent it from going into a 12V 4-pin RGB header by mistake.