As far as power is concerned, you can connect a SATA power cable to a drive using the 15-pin connector. You might require one or more power cables with SATA connectors, that depends upon if you have a split power cable or not. As for SATA data cables are concerned, you required a SATA cable for each drive. And, data cables don't have split ends, unlike the SATA Power cables. Additionally, the number of SATA data cables you require depends on the number of SATA ports you have. For example, if you have 6 SATA ports, you can't attach 7 drives to a computer.