I've got a Dark Base Pro 901 case, and I'm using all the stock fans (2 at the front, 1 at the back), but I'm adding another fan to the top. The two intake at the front have their own header, but the exhaust one at the back and top would share what's on the top panel I guess.
It has a gold connector to connect it to the case which then goes to the mother board, but then on the splitter/header thing itself it has 3 4-pin connectors, one is GND 12v (so ground?), one just has an "S" and a "P" next to each other, and the final one has "RPM" under it.

The two front fans are already connected to their splitter/header/hub thingy, and they are going in the SP one and the RPM one. Do these two connectors have the same behavior? You'd think so based on the stock fans being connected already in this way, but then why are they labelled differently? With the DBP 901, you have buttons on the front panel to control fans manually or just sync to the mobo.

I want to make sure all my fans sync and have their speed based on temperature. Going back to the back fan and top fan, which of those should go in SP and which should go in RPM ideally? Is there any difference? Weirdly, the case manual shows a fan being plugged into the GND one, but neither of the front ones are plugged into their GND one, so I assume my options for the top panel splitter are SP and RPM.