The miner itself does not have an attached power supply unit. A high efficiency power supply is recommended as it will save you money each month. I'm currently powering mine with a Rosewill Hercules 1600w that I picked up from NewEgg. I still have the power supply but I was going to use it in a server that I'm planning to build. It's a bit overkill for the server so I'd be willing to sell it for $275. IIRC they run new for $300 but seeing as I already have it and need a power supply anyways I wouldn't be willing to go any less than that.