You can also get pwm fan controllers powered through molex sata power or the like where you can connect several fans and control them via software.
Connect multiple fans to motherboard.
In fact there are a number of ways to do so.
The 2nd wire is what powers the fans and can allow you to control the fan speed.
First if you know the power ratings of your fans and of your motherboard you may be able to use a splitter such as the rosewill case fan pwm cable splitter.
Finally you can do molex straight to the fan which i don t have much experience with but iirc you need a hardware volt adapter small cable thing to avoid running at full speed at all times.
Well that depends if that fan splitters have 4 pins that means its pwm which the fan speed ia controllable you can use 4 pin splitters in 3 pin applications.
Such a splitter connects two or more fans to a single fan header on the motherboard.
Most motherboards come with two rgb headers each supplying 12v of power.
The cabled labled to rgb hub will plug into the small 6 port corsair rgb fan led hub that comes with the multi pack of fans.