https://s12.postimg.org/cxhj6qdn1/evga-g3-1000.pngThis is a typical picture. You are correct about the efficiency. Its often best at ~90% (for many reasons)
However talking about actually using 50% of your PSU's nominal capacity sounds like a completely absurd thing to do.
also to your second point, that's exactly what I meant. Just was typing from mobile via VNC, so it was kinda hard:)
(1KW DC pulls 1.1KW AC with efficiency of 0.9)
Yes, youre correct. I was not suggesting that you should buy a PSU to run it at 50%. However I would advice not to buy a PSU that youll run at 90% or more, not only efficiency starts to drop more significantly, but you also have to take into account degradation with aging
