Nvidia recommends 600W PSU for the GTX 580 and the PS should have one 75W 6-pin PCIe power connector and one 8-pin PCIe power connector. This sytem with a highly OCd, power-hungry i7 965 consumed 447W at full load with a GTX 580: http://www.guru3d.com/article/geforce-gtx-580-review/7
Your CMPSU-520HX is electrically sufficient for running the GTX 580 but lacks an 8-pin PCIe power connector; it has two 6-pin PCIe connectors. At full load it is likely that the PSU fan will max out RPM and therefore noise levels as the PSU comes closer to max capacity. The PSU is likely to work if you get the right adapters, but I would personally get a PSU that has the right connectors in the first place....or get a less power-hungry GPU.