Since there isn't any type of speed control on the Silverstone fan hub, you will have to use either the BIOS or an app like
SpeedFan to control the speed of the fans.
Your motherboard BIOS, fan controller or the app will only see a single fan.
Any fans connected to the hub cannot be controlled individually. So any speed you select will apply to all connected fans.
Make sure to use the SATA power connector if you are plugging more than two fans.