90% efficient PSUs list

[halcyon]

The 90% PSUs are finally coming to market. I remember crying out for these 3 years ago when switching amps were already at 92%. Well, here they are now:



The only question: why only 500+ Watt PSUs?

I don't need 600W of power.

I want a good 300W PSU with >90% efficiency at 80% load.

Not that the extra headroom necessarily matters that much. I'm just wondering what's the reason for this trend towards 1000W PSUs, at the time when power draw of CPUs, HDs and (soon) GPUs is going down?

Anyway, the efficiency race here is welcome.

Please post your experiences on any of the new >90 PSUs if you happen to test any of them.

EDIT: List image fixed.

MikeC has a good point later in this thread. However a valid point in industrial production would also be that as production lines are transferred over to new tech and volumes ramped up, it probably makes no sense anymore to keep producing even the small wattage PSUs with the old tech in terms of costs.

Also, why on earth are the small W psus disappearing? What is the actual percentage of people who run 2*core i7 CPUs along with four GPUS - all overclocked? Must be less than 1%, but still it seems that PSUs are being sized for this crowd. Weird. I guess the margins are better, because you appear to be selling "more".

[Mats]

Here's a link that works.

The only question: why only 500+ Watt PSUs?

Because those consumers who think that a 600 W PSU can be too powerful is a minority, that list would have looked different otherwise.

[InfyMcGirk]

The actual list seems to be within an image which is 1x1px big..? I certainly can't see any list. Maybe it's just me?

[Mats]

The actual list seems to be within an image which is 1x1px big..? I certainly can't see any list. Maybe it's just me?

Use my link instead.

[InfyMcGirk]

Use my link instead.

Yes, I was talking about your link. The first link didn't even appear as a link for me. Weird...

[nutball]

OK I'm probably talking out of my butt here (not a first ); my understanding was that it's much easier to make a PSU highly efficient at high loads than it is at lower loads (eg. why do almost all PSUs suck at the ~50W level?? Because they have to). So it's not a surprise that the first 90%+ PSUs to appear are in the WTFLOL watts range.

More cynically given the current market skew towards ridiculously over-specced PSUs common sense isn't going to come from the retail market. It may not even come from OEMs (who tend to understand the problem better than Johnny Overclocker) if the ROI of a 90%+ 250W PSU can't be demonstrated to be a win for the bottom line.

[Mats]

Use my link instead.

Yes, I was talking about your link. The first link didn't even appear as a link for me. Weird...

I don't think it did for anyone, I used the quote button and copied the address from it.
They booth seem to work now.

[MikeC]

This whole issue calls for some common sense thinking. I refer to the need/desire for high efficiency at very low power demand.

It seems logical to strive for, but it's not really.

Here are the numbers:

At 200W load, an 80% efficient PSU wastes 40W. Going to 90W makes sense, because the waste is reduced to just 22W. The cost of making a PSU 90% efficient at 200W is relatively modest, as components to do this are available in quantity. I refer to the IC power modules, etc. Increase the power load, and the argument for high efficiency just gets stronger because the watts saved keep going up.

At 50W load, an 80% efficient PSU wastes 12.5W. Going to 90% efficiency, the waste drops to 5.5W. OK, that's a 7W savings, which is not insignificant -- but are there electronic components which can achieve this at modest cost? According to PSU makers I've spoken with, not really. It's doable, but the cost is high, and people pay for rated power, not efficiency, so it's a marketing nightmare.

What happens at 25W load? This is where some low power nettops will reside at idle. Well, an 80% efficient PSU will waste 6.125W. Going to 90%, the waste drops to 2.8W. The difference is just over 3W. (Of course, this example is kind of specious because there may be no PC PSUs which are 80% efficient at 25W; I know there are none 90% efficient at this load.)

Here's my point of view on all this -- If the net savings is less than 5W, or maybe even 10W, and it's expensive to get, then it's not a practical goal. You're better off just turning out the lights, the TV, the HVAC, and the computer a half hour earlier and getting to bed for a bit more sleep. You'll save a whole lot more energy than a >5W more efficient PSU.

[GuustFlater]

This whole issue calls for some common sense thinking. I refer to the need/desire for high efficiency at very low power demand.

For a large part I agree with your comment. The savings made per Watt are not huge, until you accumulate them allthogether...

In the Netherlands, roughly per Watt for an always-on machine (I am building a new Windows Home Server), costs 25 eurocents per kWh, which is 8.76 kWh in a year and roughly 2 euros.

I see some people going for the lowest power towards a sub-20 Watt machine. I would like to do that too, but not at any price. And there you have your point. An additional 3 Watt saving may cost you a fortune, but bring you 6 euro saving per year on the electricity bill. The only motivation in going forward is the 'kick' of the very low power .....

I will be going for the 'reasonably low power machine' which should be affordable as well, and pay a few euros more per year to the electricity company.

[Plekto]

The only option that I know of would be one or possibly two PICO-PSUs. they are essentially 95-98%+ efficient in themselves, since they are DC-DC power supplies, so the only problem here is how efficient the power brick/module is. And 90%+ efficient 12V power supplies are available. It's tons easier to engineer a power supply that works efficiently at one voltage than several. And as a rule, they last far longer as well.

Most of the better ones are 95-98% efficient, which when you combine that with the PicoPSU's efficiency, is over 90%. It's not as clean and seamless as a typical PC power supply, but when every watt counts, it's the best option by far.

[Mats]

While we're talking about alternatives to regular ATX PSU's, whatever happened with the piezoelectric power supplies?