SPCR

I got this cable with my Scythe fan. I'm not using it, but wondering how it would be used. It has a separate yellow wire and plug. Is that for connection to the MB?

You would use the three-pin plug in bottom left to connect to the fan. It will get power from the Molex pass-through in the top right. It will also provide RPM reading from the fan to the motherboard via the yellow wire and plug in bottom right.

I thought in order to make that work you also had to split the fan's ground wire off to accompany the RPM wire. I guess scythe knows what they're doing, though.

In fact it works the way it is.