I'll repeat myself again, you don't need more than 550W for a 290x and i5, even with overclocks. That XFX is just a Seasonic rebrand, it's just as reliable as that Corsair which incidentally is also a Seasonic platform. That's not to mention the horrible coil whine that many TX power supplies have suffered. The EVGA SuperNOVA G2 series are Superflower Leadex platforms which are even better than those mentioned, but you don't need 750W.