Introduction, Specifications, Availability and Pricing

Technology is ever evolving and driven by innovation. Power supplies are no different and changes occur in AC to DC regulation, DC to DC regulation, improvements in cooling, reduction in noise, etc. Often times we see big changes in one particular area that raises the bar in what is considered the best. Every now and then, we come across a unit that does this not in just one category, but multiple areas of the power supply. That is just what we have from a newcomer to the U.S. in the latest unit from be quiet!.
Many of you have never heard of be quiet! in the USA and that is due to their units being available to the European market. be quiet! is a German based company known for their quality power supplies, fans and coolers. They have been awarded manufacturer of the year five times in a row by German hardware magazine PC Games Hardware and have also received recognition for the fans and coolers. As the name suggests, be quiet! focuses on second to none silent operation built into their premium quality products.
The unit that we have on the bench today is their new Dark Power Pro 10 550W unit. The Dark Power Pro 10 is available in six different wattages to cover whatever your needs may be, ranging from 550W all the way up to 1200W. The Dark Power Pro series of power supplies are known for the quiet operation and the new Dark Power Pro 10 series units add excellent efficiency to the mix.
Efficiency and silence mean nothing if the unit can't provide stable power, so read on as we take a deep look into the Dark Power Pro 10 550W power supply and see if it as good as they say it is.
Specifications, Availability and Pricing

The Dark Power Pro 10 series of power supplies utilize a quad 12V rail design and can also be configured to use these four rails. We will talk more about this in a little bit. Two of the four rails are rated for 20A each and the other two are rated for 25A each. Combined total output for the four rails is 45A or 540W. Both of the minor rails are rated for 25A each with a combined maximum current of 25A. The 5VSB rail is rated for 3A or 15W total. Combined maximum output is 550W.

We are glad to see that the Dark Power Pro 10 series covers all the features that we look for in a unit. Protection is provided against over-current, over- and under-voltages, short circuits, overheating and overloads. The unit is rated for 80Plus Gold efficiency and rated for 100% continuous output at 50C. All of the cables are fully sleeved, both native and modular.
be quiet! has an MSRP on the Dark Power Pro 10 550W of €129.00. This currently works out to be about $160. That definitely puts the unit towards the more expensive end of things when it comes to 550W units, but at the same time, there are very few units that offer the efficiency and features of the Dark Power Pro 10 in the same wattage range. Warranty for the Dark Power Pro 10 series of power supplies is for five years.
Packaging

The front of the packaging gives a great shot of the unit and lists a few features as well.

The back goes into more detail on the unit with charts depicting the I/O specifications, dimensions and cable/connector availability.

This side repeats the features listed on the back in two additional languages.

Over on the other side, we find some information about the efficiency of the unit and the SilentWings fan. Also depicted are various awards that the Dark Power Pro power supplies have received throughout the years.

Moving to the top of the box, we find a carrying handle and the URL of the company's website.

The bottom is mostly a reiteration of the front.
Inside the Box

Opening the box, we find one of the most well packed units that we have ever received. Great care has been taken to make sure that the power supply will arrive undamaged, even if the box is abused in shipping.

The top of the unit gives us a great shot at the gloss black finish used on the power supply. The I/O specification label and serial number can be found here as well.

The brand logo and wattage is displayed on this side of the unit.

The other side has the same logo as well as the warranty sticker.

Moving to the back, we see the standard AC input with on/off rocker switch. If you take a close look, you will see that the standard honeycomb mesh grill is not the very back of the power supply. The mounting edge of the unit is actually an anti vibration rubber element added to the unit to ensure that no fan vibrations are transferred to the PC case.

Towards the front, we find a LOT of modular connectors, especially for a 550W unit.

On the bottom, we can see the 135mm fan that cools the unit. The grill isn't quite your standard wire grill and adds to the aesthetics of the unit.

Included with the unit is the overclocking key or OCK. This is what allows you to switch the power supply from using four individual 12V rails to a single 12V rail. Two different keys are included in case you prefer to just insert the key into the power supply and not utilize the expansion slot key.

All of the modular cables come bundled in Velcro so that you may reuse the ties in your case. There are also five additional ties included.

Rounding out the contents of the box, we find the AC input cord, user manual, zip ties, mounting screws and thumb screws. Note that both the mounting screws and thumb screws are elongated to accommodate the anti vibration element on the back of the unit.
Cabling Arrangement and A Look Inside
[Heading]Cabling Arrangement
Included with the Dark Power Pro 550W power supply has to be the most impressive list of modular cables we have ever seen. The only native cable is the 20+4 pin Main. Beyond that, you receive five PCI-E connectors, nine SATA, seven Molex, one FDD and four fan extension cables. All of these are spread over 16 different cables.
The great thing about the list is the inclusion of short cables with single connections. This is especially nice for when all you have is a single storage drive and a single optical drives separated by quite a bit of space. No more excess cables and connectors. The four fan cables are 3-pin extension cables with an additional Molex connector on them. If the cables are long enough on your fans, they can plug directly into and be controlled by the power supply.

Rail distribution is a bit complicated with the Dark Power Pro 10 550W unit. It has four 12V rails. Two are rated for 20A and two are rated for 25A. Nowhere in the documentation we received on the unit were we able to find which connections are attached to which rails. For our testing purposes, we are using what be quiet! calls the "high performance single rail mode" by utilizing the included overclocking key.
A Look Inside

Cracking open the Dark Power Pro 10 unit reveals that be quiet! didn't just stop with making things look good on the outside. They also took care to make sure the aesthetics are taken care of on the inside with black components and a black PCB.

Primary capacitors are provided in the form of two Japanese made Panasonic capacitors.

Nippon Chemi-Con and Rubycon capacitors can be found on the secondary side of the PSU.

be quiet! utilizes their own BQT T13525-LF15 135mm SilentWings fan. This fan reaches a maximum of 12.9 db when the power supply is under full load.
Test Results and Final Thoughts
Test Results
Our load tests utilize a couple of FAST ATE active load testers and a variety of other equipment such as an oscilloscope, power conditioner, temperature probe and a power consumption meter. You can read more about our standard testing approach here.
The tests performed are based around six conceivable setups that are out there and progressively load down the PSU up to the power supply's limits or 1000W, whichever comes first. Since our test equipment's limits are higher than that of the be quiet! Dark Power Pro 10 550W PSU, we can test it to the maximum.

The above tests represent typical loads that we have measured from various systems and are meant to give a rough idea of where your computer might fall in line with our tests. Please keep in mind that each system is different and actual loads can vary greatly even with similar hardware.

Let's start by taking a look at the voltages to see how well this unit did during testing. Starting with the 12V rail, we see 2% regulation from with a total drop of .11V from start to finish. The 5V rail stayed within 1% voltage regulation and displayed a total drop of .03V. Moving towards the 3.3V rail, we see that regulation was again within 2% with a total voltage drop of .06V.
DC output quality was excellent from start to finish. Starting out, we were able to see a ripple on the scope during Test 1 where we measured noise at a low 18mV peak to peak. This steadily increased as the loads also increased. By the time we had reached around 50% load, the unit ripple had crept up to 22mV. Under Test 3, we saw that the noise on the 12V rail had crept up to 28mV while under full load.
The be quiet! Dark Power Pro 10 550W unit is rated for 80Plus Gold efficiency. This means that the power supply must perform at 87%/90%/87% efficiency at 20%/50%/100% loads respectively. As you can see, the Dark Power Pro10 550W power supply had no trouble achieving this while on our test bench.
Final Thoughts
Every now and then, we come across a product that just simply gets it right all the way around. be quiet! is taking a bold leap entering the U.S. power supply market. It is a very crowded and competitive category to compete in and not just any power supply will make it. After taking a deep look at the new Dark Power Pro 10 550W power supply, it is clear that be quiet! knows exactly what enthusiasts demand.
Even better is that they deliver everywhere with the Dark Power Pro 10 550W unit. Voltage regulation is amazing on the unit with both the 12V and 3.3V rails staying within 2% and the 5V rail within 1%. It doesn't get much tighter than that on controlling voltages. DC output quality was superb too, staying under 30mV at full load. Efficiency was also spectacular and well within the 80Plus Gold range.
Aside from the excellent power performance, the unit also delivers with a great set of features. Struggling between choosing a multi-rail and single-rail power supply? They've got you covered with the overclocking key. Tired of having a giant squid worth of cables mangle you the moment you open your case? They've got you covered with an amazing cable selection. Are you looking for silent operation? Well they have you covered again with the quietest fan we've come across and the anti vibration tips to reduce noise.
The only thing that we had a problem with was finding the rail distribution of the power supply. This may not be a big deal for a majority as we suspect most will opt to utilize the overclocking key to make it a single 12V rail as we did for testing. It would have also been nice to see be quiet! squeeze a little more efficiency out of the unit to make it a Platinum rated unit, but one can hardly complain when you have the kind of output quality that the unit currently has.
Even with that being said, the Dark Power Pro 10 550W power supply is one of the best power supplies that we have ever tested.