Bitmain Antminer S9 is worlds most popular bitcoin 7 bitcoin cash miner, with a very good lifespan. Bitmain Antminer S9 provides Stable hash rate of over 14 TH/s with variance of +-5%. if you are getting starting with mining then, Bitmain Antminer S9 is best for you, it is simple to setup, just plug a Ethernet cable and config with your bitcoin address and its good to go.
Power supply unit is not included. You will need an ATX PSU. There are 3 PCI-e connectors for +12V DC input on each hashing board and all 3 need to be connected to the PSU for the hashboard to operate. Do not connect more than one PSU to the same hashing board!