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 Power/Current Available on the +12V Rail(s) is the most critical factor.
Overclocking of the CPU and/or GPU(s) may require an additional increase to the maximum combined +12 Volt continuous current ratings, recommended above, to meet the increase in power required for the overclock. The additional amount required will depend on the magnitude of the overclock being attempted.
Cooler Master Silent Pro M 700W (RS-700-AMBA-D3) Discontinued
• OEM: Enhance Electronics
• maximum combined +12 Volt continuous current rating of 50 Amps
• two (6+2)-pin PCI Express supplementary power connectors
• Semi-Modular Output Cables: Yes
• Official Intel Haswell Compliance: No
• 80 PLUS BRONZE Efficiency Certification
• 5 Year Limited Warranty
As you can see there is way more than enough capacity to handle a GeForce GTX 970.