Very nice

Impressive results, indeed. The low +12V under load is somewhat ominous, but probably fine. I think after this review a lot more SPCR users may be switching to PicoPSU units.

That would be pretty sweet for my pentium 2 web server. I imagine it could easily handle the board along with an old 2d graphics card, net card, and one hard drive. But then I'd have to rebuild with an even smaller custom case.

Am I the only one thinking of using this device to convert an old AT power supply into an ATX power supply?

Probably

A couple of downsides which put me off them:

1) Good luck finding a 12V AC/DC brick >100W without a fan.

2) Good luck finding a 12V AC/DC brick >100W for less than £40 here in the UK.

3) a picoPSU + AC/DC brick will run about £70; an S12-330 is ~£40.

So the real niche for these things is for people with ultra-compact mini-ITX or micro-ATX setups with low-powered CPU's. If size isn't an issue the S12 is cheaper and more convenient.

It is a much bigger niche than that.

It's definitely quieter, almost regardless of size. You could get away with one fan in the system -- the one on the CPU HS -- in a <50W CPU system w/a <30W graphics card. How many CPUs fall into that category? Tons. Just check the A64/X2 TDP polls. How many vidcards fall into that category? Tons. As long as you're not a "serious" gamer, the 80W power brick will do fine.

BTW, here's a Delta power brick rated at 12V-12.5A (150W) available in the UK for £48.50 including V.A.T. You'll have to change the output connector, but that's a simple job.

I guess you're getting the prices from this store. 110W, 12V PSU = £41.13 incl VAT. PicoPSU is £45.83 incl VAT.

Compared to quiet fan-cooled power supplies they are pricey, but next to a conventional passive unit (such as a Silverstone or Antec Phantom) they are a bargain.

Passive 120w bricks definitely aren't impossible to find. It may take a bit of research, but they exist (a Lex 120w DC-DC power kit I used to own had one). Also, prices aren't that bad on eBay, like $20-40 usually.

Minor quibbles:

First page, in the table. "AC Input : 12V DC" seems kind of odd. Probably better just to say "Input". Ditto for "AC Input Current".

It's probably also worthwhile to mention that the input needs to be regulated according to the manual, which would agree with Devon's guess that the 12V is pretty much passed through untouched. That also means hooking up straight to the car cigarette lighter socket is a bad idea. Overvoltage shutdown will occur at 13 - 13.5V.

Like Jaganath pointed out, it costs about as much as a quality ATX power supply. So you could do it, but it'll cost more, has less power, probably produce more noise (due to old AT power supply) and be less efficient.

I have this little $30 100W 12V Power supply from PCChips that they used for powering their BookPCs. It is just a tiny cube with a 60mm fan--probably not at all efficient. I was wondering what to do with it since it didn't have the normal 3.3V and 5V rails, just 12V and 5V stand by. I think this could be the solution. I suddenly see a very small system without a power brick!

Interesting about brick fan noise. I have had a brick PSU powering one of my systems and my brick adapter is extremely similar to the 110/120W one featured in the review. However I think (not sure though) mine is made by liteon. The fan always stays on and while it is still a bit loud for my tastes it is nowhere near 36Db. Of course I may be mistaken since it's been a while since my PC has been loud, but I still don't think it's anywhere near 36db.

I run my old AT power supplies fanless. That's right, I just rip out the fan. So...if/when it burns out, I just swap in a new (zero cost) junked AT PSU!

Using an old AT power supply, I suppose you could power some stuff directly off the AT PSU, so the PicoPSU only needs to power the motherboard.

Alternatively, an AT PSU could be turned into an external brick by snipping away all lines except for one 12v and one ground line--feeding the computer from afar.

But really, I guess I'm too cheap to buy a PicoPSU.

Typically high-quality SPCR review.

I am all but convinced that my next build will include an AC-DC brick and DC-DC PSU. This kind of solution is a little more expensive than typical ATX PSUs, but efficiency is higher, it's significantly smaller, and most importantly, it's 100% silent. Anyone using SPCR-recommended hardware should be able to go this route.

Fanless 12V bricks can even be found up to 220W, allowing much higher-powered systems: SD11G5 external Brick PSU found!!! and Pico PSU at CES 2006.

For those considering PC hookup in a car, check out the MpegBox DSATX, which can accept unregulated input voltages between 8V & 16V and output 220W. Expensive at $190, but fully-featured, with startup/shutdown controller.

I thought the Seasonic S12-500 was the Efficiency king.
http://www.silentpcreview.com/article247-page4.html
at 87% from 200 to 400 watts.
But you do not even have it listed on this chart
http://www.silentpcreview.com/article601-page4.html

I'd be careful with a older system, as these systems often power the CPU from the +5V line, not the +12V line. With only 6A on the +5V line, the picoPSU might not work so well.

As mentioned in the article, it might indeed be hard to squeeze add-on video card to work with PicoPSU. But, there are nowadays some graphics cards that come with power supply: http://www.pcper.com/article.php?aid=201

Also there exists graphics cards PSUs that are sold separately from the card. While these are originally meant to help in situations where PC main PSU cannot sustain load generated by high-end machine, I think they might work also for the silencers. For what I know, PCI Express cards are required to handle power from slot and from power connector coming from different PSUs, so there shouldn't be any problem there.

Read through to the bottom of the pade, and you'll find a table with corrected efficiency results. The 87% that you quote was tested on our old equipment; at one point the Phantom 500 measured 90%, at which point we started getting suspicious. Corrected results for some of our older reviews can be found here, and details of our new test rig can be found here.

You've answered the questions I was going to ask. Thanks.



Rip off UK prices again

My first thought was "I must have one," even though I have absolutely no need for one right now. But after the price of the unit, and a power brick, I think I'll pass.

However, would it be possible for a person to build their own version of this, using a power brick to provide 12V, and using solid-state regulators (7805, LM317, etc.) create the 5V and 3.3V lines? The cheapskate/tinkerer in me is intrigued.

I wonder how many SPCR readers are already using these DC/DC converters? I'm using the 200w version in my current project, an Antec Aria. I'm using a 180W 12V power supply from Radio Shack. It does have a fan, but I've never been able to load it enough for the fan to start-up. So it is completely silent, even bench-marking. Here's what I'm running right now that draws any current....

Asus MATX board
P4-2.8 hyper-threading
Two 512kb ram chips
Nvidia 6200 (fanless)
Lite-on optical drive
Samsung SATA laptop drive
Wireless lan card
Modem card
AVermedia TV tuner card
One 120mm fan
One 60mm fan

I have seen no power issues at all. The AC/DC power supply runs at 13.5V all the time. The 12V rail runs about 12.7V......and drops to about 12.3 benchmarking.

I'm happy with mine.....and am curious about other people's experiences with these things.

There has to be a way to regulate the 12V rail a little better. Other more powerfull bricks might run at higher voltage like bluefront's brick from radio shack. Perhaps a power stabilizer for car applications?

Great article--I'd been wondering when this guy was going to see a review around here, but it was worth the wait.

One question: what are the odds of being able to run something like a Core Duo and one of the new NVidia 7600GS cards (which purportedly consumes 32 watts, but that claim has yet to be validated) on the PicoPSU? Core Duo + 7600GS and a PicoPSU would be sweet, but I could be way out in left field on that one...

Also, are there any 120W> brick PSUs that don't have fans? It seems like it wouldn't be needed for such high efficiency and low output--even at 120W, the brick only needs to dissipate 10-15W.

Man, don't you people read?

Beyonder - I linked to a thread about bigger fanless PSUs above. Try searching for 120W 150W 180W 220W fanless brick and I'm sure you'll find more.

autoboy - I mentioned a PSU suitable for cars above - the DSATX regulates the 12V rail to 2%. Carnetix also makes the CNX-P1260, which is a standalone 12V regulator that can survive car cranking and output 12V regulated to 5%.

absolutely awesome! What with new high performance per watt hardware coming out (Core Duo, Merom, Nvidia's midrange cards) there's no reason why this can't power a powerful midrange dual core system. I'd definately consider this for a new system, even at the extra cost, particularly if I can recoup some of that outlay through efficiency savings.

what'd be v. much of interest would be the testing of a few more power bricks to see if the Edac ones are exceptional or typical. Afterall, there'd be no point splashing out the extra, only to lose it with an unintentionally inefficient brick

Nice review! I've been running my XPM/Nforce2/XCCube HTPC using the PicoPSU and a 150W LiteOn brick. I also tested the PW200M using the same brick and powered an Opteron/Aria system with a 7800GT without any problems although the 12v rail does sag under load as the article points out. I found for SFF cases, these have a significant advantage of improving airflow by taking out the restrictive stock/proprietary PSUs and easily creating a new case vent.

A few questions for Mike/Devon:

1) For my Pico system, I noticed occassionally it fails to power up from standby (instead powers off). Might this have something to do with Pico's ability to handle transient loads or more likely unstable 12v from the brick?

2) How warm/hot did the Pico and bricks get in SPCR testing? With the Pico in the XPM system, it feels hot to the touch (notably at the square coil covers) whereas the PW200M in the Opteron system remains cool even with the 7800GT (possibly most of the loading is on 12v here so not much work being done by the DC/DC)? For my fanless LiteOn brick, I found it gets burning hot (can't hold it comfortably for more than a few seconds) even when not under heavy loads. I initially worried about this (I got it second hand) but after running the system overnight many times without problems it seems ok. Maybe the efficiency is lower on this brick, or without a fan even those few watts dissipated in the brick can make it very hot over time?

3) Most of the larger wattage bricks seem to have multiple connectors plugs running multiple wires from the brick even though they are connected to only one rail/point. What does spreading out the current do (allow thinner more flexible wires? better efficiency?) and is that really necessary? For my LiteOn (2 wires to 12v, 3 wires to Gnd) I tested using just one pair as well as connecting all wires, but didn't notice any difference. The plastic on the cheap connector plug I attached did end up partly melting in use, attesting to the high current running through, and maybe these dc jacks aren't the best solution when going above 120W?

Any chance you guys will test the 200/220W bricks you reviewed with the Shuttles, both 12v I believe.

While browsing online for SFF cases a while ago, possibly following a link from forums here, I found one (Lian Li?) with an upside-down motherboard. It looked very good except that the PSU was positioned directly over the CPU. This prevented the use of any abnormally high heatsink (which includes all the passive ones).

This would device instantly eliminate that problem, and probably make life much easier for many other SFF cases. For instance, you could suspend a HD in the space intended for the PSU. Were I rebuilding my system today, I'd be very tempted by this combination.

Would it be practical for such a device to regulate the 12V, rather than pass it straight through? As there is so much more power going through at 12V, it doesn't take much loss in regulation circuits before that's a lot of heat to dissipate from a very small device.

A websearch suggests the Xbox 360 draws about 160W (AC, I presume.) Assuming it outputs 12V, it should work well with one of these. The bricks must be available for separate purchase somehow. They should be cheap, due to economies of scale.

The brick with the xbox 360 has a fan that is rather noisy I hear.

Linus, no i did not read it but the power supplies you mentioned are not anything i didn't already know existed. These have been out for a long time. They don't operate in the same way as the Pico, just passing the 12V through. Also, the CNX-P1260 is only a 60W unit and would only be suitable for someone with a very low powered system like a bios undervolted 3000+ and onboard video. and it has a fan.

I was simply asking if there where some way to regulate the voltage of a brick so it didn't overvolt the system. 13.5V from the Radio Shack brick seems high to me and the fact that your system reports 12.7 is simply odd unless the system is not reporting the correct voltage or the pico does not simply pass 12V.

If we can find a brick with say, 150W, that functions much like the car power supplies where they can regulate the 12V to the same tolerances as the average ATX power supplies then we have a real winner IMO. 80W-90W just seems small to me. I don't really want to be limited to onboard video because my monitor is 1280x1024 and even simple games like WOW tax my 6150.

Thx for the review Mike, I have always been interested in these power supplies since i picked up a M-itx Via board for an application at work. I'm glad you raised the interest here so maybe we can all come up with a solution that works perfectly for most SPCR readers.

maybe ifyou hook up 5 of these in series with 5 power bricks... wait that would be more expensive than a standard fanless psu