I didn't mention power consumption and that's not the reason for wanting a platinum rated PSU
It is a good side effect though in a few ways.I agree these are good PSUs (I wouldn't be interested otherwise).
The sweet spot for efficiency is 50% load, a 650W Gold ran at 50% load will probably be more efficient than a 1000W Platinum ran at 30%. The trick is to pick the wattage which is closest to twice your load power draw becasue that's where you get the most efficiency and the most benefits as a result of the efficiency (less heat, noise, power consumption).
I have found with a fanless or semi fanless PSU (I've owned both), you get heat soak in the PSU that then radiates into the case. Which increases system temps and noise becasue the case/cpu fans need to idle at a higher rpm.
A more efficient PSU reduces this heat soak and choosing a wattage closest to your usage helps to take advantage of the efficiency potential.
Idealy I'd like a 650W Titanium PSU with a fan profile that is continuous but idles at a very low RPM so it's silent but stops heat soak and then ramps up when needed. The Titanium rating also offers high efficiency at 10% load so you get high efficiency all the time, both during idle/light load and under load. Which all helps keep the heat and noise down in the whole system.
It would also be good to be able to customise the fan profile in the PSU, with it being able to overide your profile should it need to. You'd then be in complete control of the heat/noise ballance.
If you just use your system for gaming and it's only on while your gaming them all this doesn't matter of course. If it's used all day much of that idle/light load and your trying to keep noise down, efficiency and more to the point the effective use of that available efficiency is important.
celtic man i am lol. Am hoping now i can overclock both my new cards.