I agree a 56 should be fine with a 500w psu providing it has a decent 12v rail.
I wasnt blaming his high power load entirely on the GPU, I just said it was high
I think the reviewers figures are high as well. I think the reason is that my cpu has very moderate voltages set (I refuse to run any cpu over 1.21v, yet many run 1.35v as routine). I also keep c states enabled, whilst many overclockers turn it all off. So I expect these inflated power stats, will be down to the cpu as well.
On my mining rig I have 2 gtx 1070s running on one 500watt PSU after someone told me I was crazy to use that PSU for 2 1070s and pulling over power 240w at the wall not even half the PSU capacity. Most enthusiasts tend to massively over provision on PSUs. Although both those 1070s are power limited to 70%.