For a system using a single GeForce GTX 560 Ti graphics card NVIDIA specifies a minimum of a 500 Watt or greater power supply that has a combined +12 Volt continuous current rating of 30 Amps or greater and that has at least two 6-pin PCI Express supplementary power connectors.
Total Power Supply Wattage is NOT the crucial factor in power supply selection!!! Total Continuous Amperage Available on the +12V Rail(s) is the most important factor.
The Corsair Builder Series CX500 V2 (CMPSU-500CXV2), with its combined +12 Volt continuous current rating of 34 Amps and with two (6+2)-pin PCI Express supplementary power connectors, is sufficient to power your system configuration with a single GeForce GTX 560 Ti.
Although the Corsair Enthusiast Series TX do have a higher quality and longer warranty period.