PicoPSU for HTPC ?

[helian]

Hi,

I'm planing a new HTPC build using:
Motherboard Intel DH57JG
Intel I3 530
2 or 4GB DDR3 1333, probably kingston
4 HD's Samsung 1.5T
1 Noctua cooler NF-P14 FLX
and a USB monitor, Samsung U70

Will a PicoPSU 150-XT be enough to power it ?


Thanks,

[shleepy]

I think that should be fine, assuming those four HDD's aren't terribly power hungry.

[MikeC]

You have to match the output of the AC/DC adapter to your needs. picoPSU only provides the lower voltage lines, taking them from the 12VDC output of the adapter. When the PC demands a lot of power, most of it is on the 12V line, so the adapter is actually more important than the picopsu.

[Namheul]

Im running the following from a 150W picoPSU, using the fanless 150W brick:

DH57JG
i3-530
4GB DDR3
500GB 3.5" Samsung
Slim DVDRW

I had a power meter, but i dont think it was accurate at all, and it would read 90W under load.

[helian]

thanks for the help guys.

[MikeC]

Im running the following from a 150W picoPSU, using the fanless 150W brick:

imo, this doesn't tell us anything useful -- brand, model #, detailed specs are needed.

[jackoakwood]

Presumably he's referring to the brick that mini-box sells on their website along with the PicoPSU.

It's got the following stats, according to their site:

12v/12.5A AC-DC Power Adapter

AC-DC 12V, 12.5A Switching Power Adapter (110/220V)
- AC adapter for higher power applications
- AC INPUT: 100 -240 VAC
- DC OUTPUT: 12V, 12.5A
- High power, 150watt/160Wattpeak
- Power Cord included
- Fanless
- 4 pin mini-din jack (Mini-Fit-JR adapter included)
- RoHS compliant

Unfortunately, being a newbie, I can't link to it yet.

[Namheul]

Im running the following from a 150W picoPSU, using the fanless 150W brick:

imo, this doesn't tell us anything useful -- brand, model #, detailed specs are needed.

Sorry, as jackoakwood said, its the one from mini-box.

Originally had the 102W one, but the fan apparently kicks in at 90W load, and my PC would occasionally hit that and the fan would turn on.

[leem]

I've had an email back from LinITX saying that the FSP 150W adaptor they sell with their PicoPSU 150-XT is fanless. I have asked Mini-box the same question about their 150W adaptor.

I need to use a PicoPSU with 24-pin ATX connector, which limits it to PicoPSU 150-XT or 160-XT. But I lam very unlikely to use anything like 150W power. I am looking for the most efficient power supply, and the 160-XT appeas to have improved electronics which make it more efficient at low loads.

When the PC demands a lot of power, most of it is on the 12V line, so the adapter is actually more important than the picopsu.

So is it the same with the adaptor: they are more efficient at high loads? In that case I should look for a 90W adaptor to use with with the PicoPSU 150-XT... I'd appreciate any advice on this

[MikeC]

All power devices have a bell curve of some description, usually a little lopsided -- highest somewhere in the middle, lower as max is approached, and lower at low power load. Here's an example of the VRM efficiency of two motherboards. Voltage Regular Modules on mobos are DC/DC converters that convert 12VDC from the PSU to the 1.xx volts needed by the CPU. VRM is just another type of power circuit.


The above is the VRM power curve of a high end server/workstation board.


This is the VRM power curve of a midrange consumer Intel socket 775 board (circa 2005).

See the differences in... max efficiency and the rate of falloff at the low end?

Now having said all that, you have to be aware that as the power load drops, % differences in efficiency actually mean less and less. At 20W load for example, a 90% efficient PSU pulls 22W from the wall, while an 80% efficient one draws 24W. 10% difference seems a lot, yet the real power difference is just 2W. In contrast, at 200W, that kind of efficiency difference amounts to a much more significant 20W.

Finally, Energy Star maintains an PDF/XLS database of efficient AC/DC converters here:
http://www.energystar.gov/index.cfm?fus ... w_code=ACD

[leem]

Thanks for this Mike, very useful... although I now notice the link towards the end of your Winmate DD-24AX review.

Do you feel this is typical, this significant difference in efficiency between a 'typical' server board and consumer board? If so, might you start including VRM power efficiency curves in your mobo tests? A trawl through some Mini-ITX reviews suggests that, for example, MSI mainboards are more power efficient. It may be useful to have some empirical data in reviews to back-up the anecdotal.

The Energy Star rating for the FSP150-AHBN1 150W adaptor at LinITX is a reassuring 90% (typical) and 0.35W at no-load: not the best of the bunch but by no means the worst.

Are you likely to revisit the PicoPSU for a review? Since your review in 2006 there has been a proliferation of new models, more powerful adaptors, of Mini-ITX boards to go with them, and a burgeoning interest in low-power systems and efficiency.

[MikeC]

Thanks for this Mike, very useful... although I now notice the link towards the end of your Winmate DD-24AX review.

Do you feel this is typical, this significant difference in efficiency between a 'typical' server board and consumer board? If so, might you start including VRM power efficiency curves in your mobo tests? A trawl through some Mini-ITX reviews suggests that, for example, MSI mainboards are more power efficient. It may be useful to have some empirical data in reviews to back-up the anecdotal.

The graphs were created by an Intel power metrics engineer (I met at IDF 5 years ago) with access to $10,000+ automated gear to measure the power throughput from ATX12V connectors to CPU socket terminals. This is to rich and too complex for SPCR. I used them just as an example. There's some interest an NGO to introduce some kind of energy efficiency standard for motherboards, and I just fielded a call from them a couple days ago about this, which is why the data was fresh in my mind. Today, for socket 1366, that gear would have to be even more complex, as the i7-1366 gets as much 30W through the main 24-pin mobo cable.

The Energy Star rating for the FSP150-AHBN1 150W adaptor at LinITX is a reassuring 90% (typical) and 0.35W at no-load: not the best of the bunch but by no means the worst.

Are you likely to revisit the PicoPSU for a review? Since your review in 2006 there has been a proliferation of new models, more powerful adaptors, of Mini-ITX boards to go with them, and a burgeoning interest in low-power systems and efficiency.

revisit picoPSU -- may be worthwhile.