It would be good to see a 350W version with similar characteristics.

A 650W PSU at 80% would waste 130W in heat and support only 520W. This would seem sensible for a gaming system, in which all other system components, CPU, GPU etc waste much more energy. But if a 400W PSU operates at say 60%, it will waste 160W in heat and support only 240W system load. Thus the PSU wastage is higher in low end PSUs than in high end PSUs in absolute terms.
We need PSUs suitable for low power HTPC with above 80% efficiency, say a 300W with 90%. This will give cool running HTPCs which are more popular these days.

nicely done, but what what cost?

I have a HP dc7900 SFF and it has a very efficient power supply. It’s a proprietary shape and uses an 80mm fan but it’s disappointingly loud even when the system is at idle. Surely it can dissipate ~5W of heat in a quiet manner!
It has a Q45 chipset, E7300 CPU, Hitachi 1TB HDD, DVD writer & 1 stick of DDR2-800. It consumes 34W at idle and 63W if I load both cores with Orthos. It’s 80plus certified and may be Bronze but I haven’t checked yet.

I did built a desktop system in 2006 using Intel’s MODT platform and using a mobile HDD and PicoPSU it idled at 20W with a Core Solo 1.66. Considering how much more powerful the HP system is I think the extra 14W at idle is reasonable.

So when will PcP&C come up with their own version with passive cooling and without the modular wires? Not that I will buy it since I just recently upgraded to the Silencer 750.

20% of 650W is 130W.

130W at 87% efficiency is 149.4W.

149.4W - 130W = 19W.

If the fan is also temperature controlled, I have some difficulty believing that the PSU fan will stay off, unless the case fanage is moving enough air to draw or vent through the PSU. Even a 5W nightlight bulb will warm up a confined area by quite a bit if it is just left running.

so the fan may not go off in a particularly cramped or poorly ventilated system.

OK, that makes little sense.
Did you mean to say that the fan may not go off in a particularly cramped or poorly well ventilated system?

80% Plus Gold certification? Somebody needs to be shot. Just call it 90% certification and be done with it.

I wonder if there's any difference between these models and the recently announced Corsair 650 & 750W models. (I'm assuming those are made by Seasonic)

I wanna see the guts.

i'm waiting for a single rail 80 plus gold. 500 W or less modular wires

Neat. I thought it would take longer before 80 Plus Gold PSU started showing up. Hopefully the price won't be outrageous.

Is that with 110V or 230V input? Efficiency always seems to be a good bit higher with the latter.

I like!

But, I already have an 80plus PSU so I won't buy another PSU for years. Oh well.