Efficiency, According to the 80 PLUS Specification


Efficiency Across the Power Spectrum


In the test lab, the 480 W power supply follows and then surpasses the performance of the 580 W model. It conforms to the 80 PLUS spec even more closely, sporting particularly high efficiency at low loads. At 25 W, for example, the 480 W PSU comes close to 80% efficiency, which is a respectable number that ranks among the best performances we've seen. In standby, it only draws 0.18 W.
Our lab tests show that be quiet!'s E9 CM 480 W doesn't encounter any regulation issues, and also achieving low low ripple and noise values on the DC rails.
Last but not least, even when you're in a quiet room the Straight Power E9's fan can only really be heard close to the power supply itself.
A Peek at the PCB
The 480 W PSU's interior looks a lot like the 580 W model we've already reviewed. All be quiet! power supplies are manufactured by FSP and are similar to that company's Aurum family. Taiwanese firm CapXon makes the Straight Power E9's capacitors. Although they're not the premium caps from Japan, which FSP uses in its own-branded power supplies, they're still decent and shouldn't cause problems.
We did notice an extra ceramic capacitor in the mains-side circuit. Its task is to eliminate the chirping sound that sometimes emanates from power supplies. Another design feature intended to help reduce noise is a fan mount sitting on rubber grommets. This prevents vibrations from being amplified by the power supply enclosure. The manufacturing and soldering quality are both impeccable. Our only complaint is that FSP does not use heat shrink tubes to cover the locations where cables are soldered onto the PCB.
The be quiet! Straight Power E9 CM 480 W is very quiet and boasts an 80 PLUS Gold rating. It demonstrates no apparent weakness in our testing, and offers high efficiency across the entire load spectrum. Its feature set and quality are top notch, and although it is actively cooled, this power supply is the next best thing to fanless. Unfortunately, it isn't available to our U.S. audience, and only stands in as a comparison point for our other two passively-cooled contenders.
- Two Fanless Power Supplies, Compared
- be quiet! Straight Power E9 CM 480 W
- Measurements: be quiet! Straight Power E9 CM 480 W
- Seasonic X-460 460 W
- Measurements: Seasonic X-460
- SilverStone SST-ST50NF
- Measurements: SilverStone SST-ST50NF
- Test Setup, Hold-Up Time, Inrush Current, Peak Load, And Short Circuit Protection Test
- Efficiency According To The 80 PLUS Spec, Temperature, And Standby Power
- Efficiency Across The Power Spectrum
- Which Fanless PSU Is Right For You?


Last time I checked, Americans aren't the only ones who enjoy a silent computing experience...
Many companies that are focused on silence such as Noctua and beQuiet! are not "American."
I think it is quite neat that they have fanless option. I would never take the risk, but if I did I would chose seasonic, my 750W has done me well.
Last time I checked, Americans aren't the only ones who enjoy a silent computing experience...
Many companies that are focused on silence such as Noctua and beQuiet! are not "American."
--> argument over.
For the record I am not an American and I don't live in the US
I've been buying Corsair and even $45 Thermaltake 500... and I cannot hear them... with the cover open. The problems with FANLESS PSUs and GPUs is that they become heat-sinks... sure they are quiet, but everything around them gets warm. You need to blow the hot air out.
Going from a fanless GPU to something with a huge fan (H.I.S. brand) - the fans barely makes noise and use a rear exhaust and I can run the system fans at a lower speed.
Mitko: get soundproofing material, apply to inside of case. Put case on floor.
My case is on the desk, a foot or so away from me... its no louder than the A/C vent blowing air in the room.
1. The heat stress is the factor No. 1 for the lifespan of the capacitors, no matter if they are conductive polymer or very high quality electrolytic brand.
2. The case should use more higher intake flow to make sure that the power supply's heat does not enter the case.
3. A noise level of 10-13 dB can be tolerated for the sake of sustainability and avoiding the risk of heating up your case with the heat from from the PSU.
Personally, in the last 10 years I admire Seasonic for their stile... But I would use a passive solution that is still in the PC case just for a while.
most of the voltage regulators are mostly the same though they may add a larger heatsink on them.
you could pretty much turn a standard PSU into a silent one by swapping the caps and heatsinks. High quality capacitors are about 3-5 times more expensive (may take the cost of a single cap from 5 cents, to around 15-20 cents)
Yeap, and you get a better, more reliable, energy efficient bit of kit too. Bit I don't think I'll be having a go a swapping them
Not an 'American' thing, but a medical one. Noise pollution is becoming more and more of a problem; and affects long term hearing quality.
No wonder people can no longer hear the difference between an MP3 and a CD recording.
Every now and then you can find it on sale for $120. A steal for the best 650W PSU in the world.
it'll be used in an HTPC/home media server. to those that have doubts about the usefulness of such a PSU, I will ask: "what's the point of having that nice audio system in your living room if all you're gonna hear is fan noise in the background?"
Another article is what got me hooked http://www.silentpcreview.com/Seasonic_X-400_Fanless_PSU, they basically had to resort to a hair dryer to make the thermal protection trip. A very good power supply that can put up with alot of heat before having to shut down.
translate please...don't understand...thanks in advance