To keep the mining equipment running stably, you need to use two power supplies with sufficient power to make your rig much efficient. A miner has to adopt a 80 PLUS Gold certified power supply to make sure that a power supply will achieve at least 80% efficiency for the power output and stably offer sufficient power to the system.
If you are going to optionally install 6 AMD Radeon R9 280 VGA cards at the same time, you must calculate the power requirements of two power supplies separately for estimating the maximum power consumption from all the devices precisely. Please follow the rules below to choose the appropriate power supplies and calculate the total power you may need for the Bitcoin mining hardware:
1.First, the Power Supply 1 should be 750W at least. It offers the power to one graphics card, and the other devices, such as CPU, memory, HDD and so on.
2.Second, the Power Supply 2 should be 1600W at least and it offers the power to the other five graphics cards.