Yes; you are fine with that PSU. Also, wattage is not the most important thing, but rather the combined amps on the +12V rail. The PSU is required to have two 6-pin (or 6+2-pin) PCIe supplementary power connectors and a combined current rating of at least 12.5A on the +12V rail. The PSU that you bought is a Corsair CXM 500W. It comes with two 6-pin PCIe power connectors and a single +12V rail of 38A. So it is more than sufficient to power your GPU with room for overclocking. And it's a good quality PSU.