"Am i the only one that thinks power usage in a PC is out of hand ? I mean .. in the past we were on a 250 W PSU.. now you need 650 W GOLD PSU to be sure your PC will run without issues .. and now we have 2KW PSU .. i hope in 10 years this won`t be standard PC requirement ... "
Nope, mabye in the past, but not anymore. There was a steady rise in the power requirements of a mid range system or upper end system until about 2009 or so. After that things have been going the other way.
Assuming for a moment we ignore sli/crossfire setups, or other dual chip configurations. And ignore mad overclocking... A high end graphics card is like 150-220 watts. High end cpu about 80-120 watts, rest of the system doesn't take that much. About 400 watts or so under full load. You dont want to load a psu to its max, or you will kill its life/stability/efficiency. So assuming 75%, and you come out to a 533. A 500-550 watt power supply is enough for high end single gpu.
Now if yous tart going multi GPU, and multi cpu, you start running up power fast. But even if you have 4 gpus, and 2 cpus, you are still under 1200 watts, and a 1500 watt power supply would be sufficient without excessive load.
I dont even see how you could load a 2000 watt power supply with 1 system. I cant add up 1500 watts worth of load in any possible single system desktop configuration. Unless there is a motherboard that can take like 8 gpus, and you can sli/crossfire 8 gpus, which i dont think you can.