System Power Supply Requirements for a single NVIDIA Reference Design GeForce GTX 980 Ti
• NVIDIA specifies a minimum of a 600 Watt or greater system power supply. (Minimum system power requirement based on a PC configured with an Intel Core i7 3.2GHz 130 Watt TDP processor.)
• the system power supply must also have a maximum combined +12 Volt continuous current rating of 38 Amps or greater
• the system power supply should also have at least one 75-Watt 6-pin and one 150-Watt 8-pin PCI Express supplementary power connectors. There are some non-reference design cards that require two 150-Watt 8-pin PCI Express supplementary power connectors (E.g. EVGA GeForce GTX 980 Ti Classified ACX 2.0+ [06G-P4-4998], GIGABYTE GV-N98TG1 GAMING-6GD, MSI GTX 980TI GAMING 6G).
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.
Thermaltake German Series Hamburg 530W (W0392RE)
• OEM: Sirfa
• maximum combined +12 Volt continuous current rating: 38 Amps <===== Borderline Sufficient
• two 150-Watt (6+2)-pin PCI Express supplementary power connectors <===== Sufficient
• Ambient Temperature Maximum (i.e. without derating): 40°C
• Modular Output Cables: No
• Meets Official Intel Haswell Compliance: No (+12V rail goes above the max. +12.6 allowed by ATX12V Specs. during Official Intel testing procedures)
• 80 PLUS STANDARD Efficiency Certification
• 3 Year Limited Warranty
You haven't specified your complete system configuration so that's all the info I can provide for now.