For a system using a single GeForce GTX 970 graphics card NVIDIA specifies a minimum of a 500 Watt or greater system power supply. The power supply should also have a maximum combined +12 Volt continuous current rating of 35 Amps or greater and that have at least two 75 Watt 6-pin PCI Express supplementary power connectors. Some of the non-reference design GeForce GTX 970 cards require one 6-pin and one 8-pin PCI Express supplementary power connectors (e.g. MSI GTX 970 GAMING 4G, MSI GTX 970 GAMING 4G LE).
Total Power Supply Wattage is NOT the crucial factor in power supply selection!!! Sufficient Total Combined Continuous...