Please show your work for this problem.

This was incorrect -- correction reads: 87% efficiency was reached at just over 150W, which is a bit higher than 20% of rated load (140W).

Cougar is HEC. (But it's kinda confusing because HEC has its own Cougar series PSUs which are different from HEC's Cougar brand's PSUs)

I assume that your 240V line is 60Hz. Aren't most (all?) of the 240V countries 50Hz? Is this a valid test?

Perfectly valid.

Mike,

I wish that some enterprising PSU new breed like Cougar would introduce a line of ATX 12V 2.3 80Plus Gold modular PSUs aimed specifically at the HTPC market. I know that Cougar is a Euro gameboy company, but there are already plenty of megawatt PSUs like the GX-700 subject of this review. On the other hand, the HTPC market craves low noise system operation that begins with a very efficient PSU that has a wiring harness that improves air flow rather than blocking it. Of course, Seasonic is out there with their $150 X-400 PSU, but goodgodalmighty, and who needs 400 Watts anyway. Let me use my half-assed little HTPC as an example. It includes:

1. ECS H55H-I Motherboard – 15 Watt, about - Specifically because it doesn't have that NEC USB3 chip to suck down 5 more Watts.
2. Intel Core i3 530 CPU/IGP/Northbridge – 15 Watts at the desktop, 45 Watts playing Blu-ray – Specifically because the next CPU down, G6950, had a lower speed 533 MHz IGP while the 530 IGP runs at 733 MHz. As it turns out Anand gave us all a bum steer when he advised that the 530 would be perfect for decoding Blu-ray. That was a bucket of bullshit.
3. G.Skill F3-10666CL7D-4GBECO 2x2GB DDR3-1333 1.35Volt DIMM pair – Vanishingly small power.
4. Intel SSDSA2MH080G2R5 80GB SSD system drive – 1 Watt.
5. WD WD5000BEVT 500GB HDD data drive – 2 Watts.
6. LG CH10LS20 Blu-ray reader – 2 Watts, when in use.
7. Rosewill RHUB-300 USB Hub – 1 Watt, maybe.
8. Seasonic SS-300ET Bronze – 7 Watts at the desktop, 13 Watts playing Blu-ray.

My HTPC system total power comes up to 43 Watts at the wall when at the desktop and 79 Watts at the wall when playing Blu-ray. Lets round this up to 100 Watts and then buy a 200 Watts 80PLUS Gold completely modular PSU that comes with a big slow cooling fan. Lets pay $75 for this great PSU, maybe a few dollars more. That should be fairly profitable for a PSU company. Maybe not rape type profits like gameboys offer, but still pretty good. In fact, going gold would halve the burn of the PSU, bringing my HTPC down to 40 Watts at the wall when at the desktop and 72 Watts at the wall playing Blu-ray.

A 200 Watts Gold would still allow me to change to the MSI H55M-E33 microATX motherboard that would support an ATI HD 5450 graphics card that really handles Blu-ray, as opposed to the 530 IGP that just barely does, and a Hauppauge WinTV-HVR-2250 TV Tuner card, to accommodate Microsoft's unbridled lust to be in complete control of anything they touch. This modified HTPC system might push up close to 90 Watts, very, very worse case, and since the two new cards are low-profile PCIe ones the chassis would have to be thick enough to allow an ATX12V PSU to be mounted. I started out trying to assemble an HTPC thin enough to look like a Blu-ray player, but the technology just isn't there yet. But one thing's for sure, there is definitely a place for 90% PSU efficiency to get quiet operation.

OrvilleP --

Here is Seasonic's reply to a query I made about why they're not offering lower power 90% efficiency PSUs:


Currently, for super lower power rigs, a high efficiency AC/DC adapter + DC/DC board is the only truly cost/energy efficient silent option.

Mike,

I'd just guess that Seasonic's marketing speak means “We're not sure there is a profitable market down thereâ€

From what I gather, the HDD and NAS sales never really suffered a slowdown even through the last couple years. Some store execs kept telling me -- it's the only thing that is still moving. So my take is that in many tech-savvy homes (and SOHO that don't need traditional servers), NAS has already been embraced, which helps explains the amazing profusion of those devices recently.

I agree that there's a market for high eff. 200W power supplies, but with the high diversity of form factors in the minipc market, it's not clear that any one form factor device will dominate. If someone drove a case/psu standard for miniITX like ATX, you'd see concerted effort and competition by psu makers. In the absence of such, high eff. low power devices are going to remain in the realm of special partnerships between OEM psu makers and big system integrators like Dell, HP, Apple, etc. Seasonic may get there, they're pretty active and successful as an OEM, but not necessary through the retail/DIY market.

I love cougars