To begin, some background. You plan to get a case that comes with three RGB fans pre-installed. To be sure we give the right advice, tell us exactly what case (maker and model) so we can look up its specs. We need to know particular details of the fans and how they are to be connected.
RGB fans are just fans that have LED lighting items in three colours mounted in their frames. They really are two devices in one unit - a standard fan (in your case, VERY likely one designed for case ventilation and not for use on CPU heatsinks or radiators), and an RGB lighting unit. Each such fan comes with TWO electrical cables. One is for the fan motor and ends in a female standard fan connector about 3/8" (1 cm) wide with 3 or 4 holes in it, and two ridges running down one side. It may be either a 3-pin older type, or a newer 4-pin PWM type. The second cable is for the RGB lighting units and ends in a wider (about 1") female connector with 4 holes in a straight line, commonly. This MAY be pre-connected in your case to some RGB lighting control system, but if its connectors are one of the common types you can, instead, connect them all to a mobo RGB header IF your mobo has the correct type.
These days RGB lights for computer cases come it two common different and INcompatible types. One often is called plain RGB, and it uses a 4-pin (and hole) connector type that supplies 12 VDC power to the lights and three separate Ground lines, one for each colour. The connector has one edge marked to indicate that the +12 VDC line is at that end, and the mobo header also is marked so you MUST align those when making a connection. The lighting device contains LED's of three colours - Red, Green, Blue - and in the light strip (or fan frame) all the LED's of one colour are connected together in parallel along the strip; two other lines connect the other two colors similarly. The RGB controller switches each colour on and off, allowing a wide range of colours as they change and mix. But at any one moment, the entire strip is all the SAME colour.
The more advanced system is called Addressable RGB or ADDR RGB or ARGB. It uses a connector that looks VERY much like the other one, but with one of the pins missing (hole plugged) so it is a 3-pin system. Those pins supply common +5 VDC and Ground lines and a Control Line. All along the strip, the LED's are grouped into Nodes, each consisting of one LED of each of three colours, plus a controller chip for that Node only. All the Controller Chips listen to the Control Line, and each chip has its own unique address. When it receives an instruction packet for its address it does whatever it is told with only the three LED units in its Node. Thus at any one time, all Nodes along the strip can be different, and more complex colour patterns are possible like rainbows, stationary or chasing down the strip. Because of both the voltage (12 vs 5 VDC) and the control mechanism, these two systems cannot be mixed together in one circuit.
For either type of RGB system, it is common to have only one header on a mobo. In your case, OP, your mobo has two headers, both of the plain RGB type (4-pin, 12 VDC) - see your mobo manual on p.32, the RGB LED Header and the AMD Fan LED Header. Both of these work the same and have identical electrical properties, but they are labelled differently to help you keep them straight. NOTE that a third header (p. 29, AMD LED Fan USB Header) is NOT of this type - it is a special header used only for particular models of AMD CPU cooler systems. So, that gives you two plain RGB headers on the mobo that you could use to power and control the RGB lights in your case fans IF they are of that same plain RGB type (hence the request for case details), and IF their RGB lighting cables end in connectors that can work. If that can be done, the mobo comes with a CD of tools that will include the ASRock Polychrome Sync software that you install and use to configure the RGB lighting capabilities of the mobo headers. BUT you have three such fans. You will need to use a RGB Splitter, like this
https://www.newegg.com/p/1W7-005X-0...cm_re=RGB_splitter-_-9SIACJF8XR5093-_-Product
That's a 2-pack of 4-pin plain RGB Splitters. Each Splitter converts one mobo male header into three, and has female connectors on both ends, but includes gender-changing adapters to convert the outputs to males.
Now back to FAN connections. Your mobo has one CPU_FAN header for use with the cooler of your CPU (p. 31), and two CHA_FAN headers (p. 30), one each of the 3-pin and 4-pin type.You would use one of those headers for all of your case fans, very likely - which to use depends on the type of motors in the included case fans. And just tonbe sure that this is acceptable, again we need the case specs so we can determine the current draw needs of the fans. Either way, you are likely to be connecting three fans to one header, and that will require a FAN Splitter (different from the RGB Splitter) like this
https://www.newegg.com/p/N82E168124..._re=Coboc_fan_splitter-_-12-423-163-_-Product
So, tell us the details of your case and we can complete the advice on exactly how to hook this all up.
Facebook
Twitter
Instagram