Seasonic X-400 Fanless for a low-power system?

[wendell]

I'm looking to build a low-power system (Intel Atom, 2 x 2.5" HDD, 1 x ODD) and for the case am leaning toward either the Apex MI-008 or Lian Li PC-Q07. I plan to use a Scythe Quiet Drive for the OS HDD and either a Noctua or Nexus Real Silent for a case fan if needed.

For the PC-Q07, the X-400 appears to be the quietest PSU, but I'm concerned that it is not suited to such a low-power system. Would there be issues with heat or noise? Is there something else of lower power that is just as quiet?

I sort of considered the picoPSU, but am not very fond of the power brick thing.

[quest_for_silence]

Is there something else of lower power that is just as quiet?

These are the acoustic performance of the PSUs here tested out of the hotbox in the last 18 months: as you may note, under 90W they all have quite similar noise level.

Code: Select all

               WATTS/DB
MODEL     90 150 200 250 300 
                               NEWEGG
AX-850   <10 <10 <10 11~13 12   190$
TP-750    12  12  12  14  15    120$
X-400FL  <10 <10 <10 <10 <10    130$
MODU87+   11  11  11  11  11   >130$
NX5000    11  11  12 12.5 14    100$
ECO80+   <11 <11  12  16  20     80$
X-650    <10 <10 <10 <10 <10    140$
CP-850    12  12  12  12  12    120$

Anyway, any ATX PSU for an Atom and two disks is a total waste of money and space. IMO.

I sort of considered the picoPSU, but am not very fond of the power brick thing.

Check Oklahoma Wolf own test: the Fortron 19V wins hands down.

[dhanson865]

the X-400 appears to be the quietest PSU, but I'm concerned that it is not suited to such a low-power system. Would there be issues with heat or noise? Is there something else of lower power that is just as quiet?

I sort of considered the picoPSU, but am not very fond of the power brick thing.

No, fanless is fanless and any fanless PSU will either be a brick or will be rated for a similar wattage to the X-400. You can get higher wattage PSUs like the X-560 but finding something lower/cheaper than the X400 that isn't a brick solution is going to be a waste of time.

[wendell]

Fanless PSUs are not all alike with regard to heat and sound. There have been several mentions in this forum of buzzing with the Seasonic X-400. I'm concerned with how much of an issue that might be at the low power loads I'm expecting. Also, I'm concerned about relative ventilation needs.

I've also been looking at fanless PSUs from FSP and SilverStone. The Fortron Zen series appears to have significantly more buzz, heat, and failures. The Silverstone Nightjar series on the other hand looks like it has less of a noise problem.

The SilverStone SST-30NF 300W is still available. I'm wondering if that might work better for a compact, low-power setup like I described.

[dhanson865]

Fanless PSUs are not all alike with regard to heat and sound. Also, I'm concerned about relative ventilation needs.

I agree and when I said fanless is fanless I meant there is no magic.

Higher efficiency = less heat

At 65W the X400 is 84.5% efficient and the Silverstone 300 is 76% efficient. So if you are worried about heat you go with the X400. Clearly it is more efficient at lower power draw scenarios.

As to buzzing there have been threads on SPCR about buzzing components for as long as SPCR has existed. No product or company is safe from this possible issue.

Some theorize that AC power affects it and suggest adding or removing a UPS or surge protector or switching for a different kind of UPS or surge protector.

Some have found that so called buzzing PSUs don't buzz on their own. Take PSU A and plug it up to motherboard B and it the PSU buzzes, Take PSU A and plug it up to motherboard C and no buzz.

viewtopic.php?f=6&t=41464 went 214 posts and I don't think there was a solid consensus on exact causes for every noted case.

One particular poster on SPCR says he has tried everything

I at first though the buzz was related to the mobo, and tried various different ones with the hx520. it drove me crazy. I eventually went through many mobos trying to get a mobo that didn't cause my psu to buzz. i tried a few other power supplies as well, and they buzzed. it seems like almost every PSU these days has a lot of buzz in them. I tried an S12, 2x hx520s, 2x antec earthwatts, 2x antec NeoHE.... all coil buzzed. Really really really unacceptable. I am still unable to find a PSU without buzz.

With any luck you won't have a problem at all but the only way to be sure is to build the system and plug it in. Anything else I say would be guess work.

Wait a second, I just googled APEX MI-008 and a ATX power supply won't fit in that case. Are you planning to run with the case open? Or is that the case you'll go with if you are forced to use the PicoPSU? The Lian Li PC-Q07 will hold a normal sized PSU.

If you are serious about the Apex MI-008 and avoiding PicoPSU then maybe you want a FSP Group FSP300-60GHS-R 300W Micro ATX 80 PLUS Certified Power Supply? It isn't fanless but it'll fit in the case.

[westom]

Fanless PSUs are not all alike with regard to heat and sound. There have been several mentions in this forum of buzzing with the Seasonic X-400.

Most every desktop works fine with only one chassis fan. A fan is necessary so that the computer can operate even in a 100 degree F room. Therefore the PSU fan is not just about cooling the PSU. It is also the only fan required to move air through the chassis.

Cooling traditionally means moving air across components so slowly that your hand cannot even feel it. That gentle flow is massive cooling. And enough for most every component to work in that 100 degree F room. Routine was to operate most every computer in a 70 degree room with no fan. But all computers must also work perfectly ideal in a 100 degree room. Therefore one 30 CFM fan is installed to move air through the PSU and chassis.

This is also why better laptops hardly ever use the fan. Laptop fans run only when really required. Select a fan by determining power and by learning a fans CFM. Generally, a noisier fan of the same size (80 mm) also moves more air. Generally, a larger fan (120 mm) moving the same air is quieter. These many different versions for each fan size can be purchased from electrical supply houses.

Buzzing is a problem created by manufacturing. Wire is wrapped about a core to create a coil or transformer. Then that wire is sealed. But sometimes that wire does not sit tight and get held by the sealer. Then that wire is vibrated by the electricity (and resulting magnetic fields) passing through it. No magic device will solve the loose wire problem.

[wendell]

I just googled APEX MI-008 and a ATX power supply won't fit in that case.

I'm looking at the Lian Li PC-Q07 and the Apex MI-008 because those are the smallest cases I could find with 2 x 3.5", 1 x 5.25". I know the Apex takes an SFX PSU and have also been looking for the quietest SFX. It seems there aren't any fanless SFX PSUs. Since the one in the MI-008 is reported here to have a quiet fan, I'd probably just keep the stock configuration.

Deciding between the PC-Q07 and the MI-008 is partly a matter of whether 2 x 2.5" in Scythe Quiet Drive plus 1 low-RPM 120mm case fan would be quiet enough that going to a fanless PSU would make a difference.

From the reviews, I see that the Silverstone Nightjar ST45NF runs significantly cooler than the ST30NF. So that eliminates the ST30NF.

While the Seasonic X-400 has significantly higher efficiency, the Silverstone Nightjar ST45NF runs cooler. That, combined with the external heatsinks, makes me think the ST45NF migh be better for the PC-Q07's cramped aluminum case. Although, I don't like that the ST45NF appears to have a high power draw when idling.

[MikeC]

If you have 3 other noise sources already, then there is NO benefit whatsoever to going fanless. Just pick a fan cooled one we have reviewed that is really quiet at <100W, & efficient & cheap enough for you.

[wendell]

If you have 3 other noise sources already, then there is NO benefit whatsoever to going fanless.

Ah...I didn't realize the components I chose would already raise the noise level that much. So I guess that makes this question moot for my current project.

Still, I'd like to hear anything on Seasonic X-400 versus Silverstone Nightjar ST45NF. I could see doing something, someday, with an AMD Fusion or other cool mobo and an SSD for the OS.

[MikeC]

If you have 3 other noise sources already, then there is NO benefit whatsoever to going fanless.

Ah...I didn't realize the components I chose would already raise the noise level that much. So I guess that makes this question moot for my current project.

Still, I'd like to hear anything on Seasonic X-400 versus Silverstone Nightjar ST45NF. I could see doing something, someday, with an AMD Fusion or other cool mobo and an SSD for the OS.

The X series stomps any other fanless PSU out there, the others aren't even in the same ball pack. Maybe not even playing the same game! Did you read this? http://www.silentpcreview.com/Fanless_P ... st_Roundup

For your system, it is such an overkill tho. I think you would be better off with a http://www.silentpcreview.com/picoPSU or http://www.silentpcreview.com/Winmate_DD-24AX

I guess the main advantage of the X-400 is no fuss, no muss, single ATX12v product, modular cabling, drop it in & forget about it, long warranty. But since the X560 or X650 are so close in price to the X400, and their fan does not even start spinning till nearly 200W (in the SPCR PSU test hotbox), maybe one of them is a better choice -- for possible use later with other more power hungry systems...?

[wendell]

For your system, it is such an overkill tho.

I've read your very informative reviews of these PSUs. The thing that interests me about the SilverStone ST45NF is that while it is less efficient than the Seasonic X-400, you report that it is significantly cooler. That shouldn't be, but there it is.

When you look at potential power versus the draw of an Atom system, yeah, these 400W PSUs look like way overkill. But if I were to get a picoPSU + power brick, that would be around $100. So, for a little more, I could get an ATX that would be a little more convenient to work with and a lot more versatile should I want to reuse it in a different configuration down the line.

[quest_for_silence]

But if I were to get a picoPSU + power brick, that would be around $100.

Then why don't you spare 50$, and get this ATX one?

And when you will be "down the line", you should have a perfect, cheap reference/back-up unit (as every PC builder should have for testing, troubleshooting or just emergency cases).

[jamotide]

Except for the quiet buzzing, the x-400FL is perfect. At my low loads (60 to 130w) it does not get warm at all, even without airflow in the case. People often mention seasonics warning, that that the case needs to have ventilation for the x-400, but that is false. I have the warning in front of me, and it mere says that the x-400 is only responsible for its own cooling and will not help with the rest of the system as a PSU with fan would. In my case is has a terrible location, on top of the cpu cooler, with the ventilation holes of the PSU against the roof of the case which has no holes. I even put a piece of cardboard to close the back of the case to dampen the buzzing.

Now the buzzing can be a problem if your case is open. But in a closed case it cant be heard anymore. Putting some dampening material around the PSU would help, too. It is not very loud even with sentive ears. Still it is annoying that such an expensive and otherwise perfect product has such a flaw.

Efficiancy is brilliant, my previous PSU (Enermax Liberty 400) was already pretty efficient, but with the x-400 power usage in idle went down from 86 to 70 watt. Under load 140 to 120w.

[MikeC]

I've read your very informative reviews of these PSUs. The thing that interests me about the SilverStone ST45NF is that while it is less efficient than the Seasonic X-400, you report that it is significantly cooler. That shouldn't be, but there it is.

Not sure where you read that... but you have to keep in mind this simple fact: Thermometers and temperature readings are guides to how hot something is getting... but AC power input minus DC power output is a near-absolute measure of total heat generated in a PSU. It is possible that because the Seasonic is so openly vented & our infrared thermometer can "reach" all the way into the actual transistors inside the PSU, naturally, the "observed" temps are high... higher than seen with the more closed Silverstone. But there is no doubt that because of its higher efficiency, the Seasonic generates less heat. (BTW, don't confuse the ST40NF w/ the ST45NF -- the latter is made by Etasis; it is superior than the ST40NF made by FSP.)