Hi. A Molex plug (4-pin) from your power supply unit can be plugged into the connector. If you don't have a Molex plug available but you do have an unused SATA plug from your power supply unit, then you can use the included adapter. The Molex plug from your PSU is the third plug from the right in the image below while the SATA plug is next to it on the right. You should check to see if you have a Molex or SATA plug available. I can't say whether the extra power is needed but I think it would be better than not having enough. If you are worried, I would plug in the connector just to be safe.