You will need an ATX PSU with at least 9 six-pin PCIE connectors. There are 2 PCI-e connectors for +12V DC input on each hashing board and both need to be connected to the PSU for the hashing board to operate. Do not connect more than one PSU to the same hashing board. Bitmain recommends the APW3++ to power the L3+
6. Separate power supply to control board: there is one additional 6pin PCI-e connector on the IO board which must be connected to the PSU to get power. Be sure to power on the miner only after all the 9 PCIE connectors are connected to power supply.