Be Quiet! Dark Power Pro 10 850W - Introduction

Some weeks ago we had a look at the Dark Power Pro 10 650W, the first power supply that we received from Be Quiet!, an European manufacturer which is just starting to enter the North American markets. Today we are having our second review of a Be Quiet! power supply, the Dark Power Pro 10 850W. Although the name and even the appearance of these two products is virtually identical, the 850W version is based on an entirely different design which boasts even better performance and higher efficiency.  Can it really be that much better than the already excellent 650W version? We will soon find out.

Dark Power Pro 10 850W

Unfortunately, although they are readily available in Europe and even some Asian countries, availability remains a great issue with Be Quiet’s products in the US and Canada. The 850W version can be found at Newegg for $239.99 plus $5.99 shipping. This is slightly higher than the MSRP of the power supply is virtually no competition at all in the North American market as very few retailers carry Be Quiet! power supplies. The Be Quiet! Dark Power Pro 10 MSRP prices for the US market are:

be quiet! DARK POWER PRO 10 550W


be quiet! DARK POWER PRO 10 650W


be quiet! DARK POWER PRO 10 750W


be quiet! DARK POWER PRO 10 850W


be quiet! DARK POWER PRO 10 1000W


be quiet! DARK POWER PRO 10 1200W


Dark Power Pro 10 850W grill

 Manufacturer’s features and specifications

Continuous power (W)


Peak power (W)


Form factor ATX 12VVersion


Form factor EPS 12VVersion


Modular cable management


Special technology


Voltage (Vac)

100 - 240

Frequency (Hz)

50 - 60

Input current (A)

10 - 5



Power factor at 100% load


Compliant to Intel C6 mode


Power consumption in standby (W)


Average life time (h / 25°C)


Operating temperature up to (°C)


12 V Rails (Multi-Rail operation)


12 V Single Rail operation


Overclocking key




+3.3V (A)


+5V (A)


+12V1 (A)


+12V2 (A)


+12V3 (A)


+12V4 (A)


+12V5 (A)


+12V6 (A)


-12V (A)


+5Vsb (A)


Max. combined current 12V (A)


Max. combined power 12V (W)


Max. combined power 3,3V + 5V (W)


Hold-up time (ms)


Unboxing the Dark Power Pro 10 850W

 The box

Be Quiet! supplies the Dark Power Pro 10 850W power supply inside a very sturdy and well-designed cardboard box, with a very serious artwork theme, mainly based on a picture of the power supply itself. Inside the large box, the power supply is very carefully packed and sandwiched between thick packaging foam.

 The box rear

A lot of information may be found on the back side of the box, ranging from the list of features down to the length of each individual cable, making the packaging itself essentially a basic manual.


Be Quiet! is known to be a company which offers the richest of bundles with their premium power supplies and the Dark Power Pro 10 850W unit is no exception. Inside the box the user will find the typical A/C cable, a good manual, five black 3M screws plus five black thumbscrews, a few basic cable ties, ten high quality cable straps, a bracket with the OCK switch (more on that later), a jumper to bypass OCK and even four cables which provide eight extra 3-pin fan connectors.

 Modular cables

The company supplies the modular cables of this power supply not inside a reusable nylon pouch but in a strong cardboard box. The box may still be used for storing the excess cables and might be a more elegant solution than a pouch for some. Be Quiet! has been generous with the number of connectors, allowing the unit to power dual CPU and three-way GPU configurations. The picture below depicts the length of each cable and the number of connectors.


External Design of the Dark Power Pro 10 850W

 Dark Power Pro 10 850W full view

Be Quiet’s Dark Power Pro 10 units surely do not look anything like basic power supplies, as the company obviously spent a lot of time and effort to make the series visually unique. Aside from the obvious proprietary fan cover which sports a distinctive design of parallel wires, Be Quiet! also installed a soft plastic frame at the front of the power supply and a rubber strip surrounds the rear of the chassis, both in order to limit metal-to-metal contact and absorb vibrations. Note that the non-standard chassis is several centimeters longer than typical ATX designs, measuring 7.5 inches deep, which could be a problem with small and HTPC cases.

Side Sticker 

Large metallic stickers with the unit’s model and 80Plus Platinum certification badge cover the sides of the Dark Power Pro 10 850W. The high quality stickers are perfectly applied inside an embossed area. Be Quiet! installed the warranty sticker on the side of the power supply instead of on a screw, as not a single screw is actually visible.

Top sticker 

The sticker with the electrical specifications of this power supply can be found at the top of the chassis. Be Quiet! placed it facing the right side of the unit, so that it will be readable from the outside of a windowed computer case if the PSU has been installed below the motherboard tray.

Front side 

A small sticker indicating the model’s series and wattage can be seen at the front side of the Dark Power Pro 10 power supply. This sticker along with the plastic frame are the only things which differentiate the front side of the Dark Power Pro 10 from that of the majority of modern power supplies.

 Rear side

Unlike the front side of the Dark Power Pro 10 850W power supply, the rear is nothing alike that of a common power supply. Be Quiet! replaced it with an aluminum plate, forming a frame for the connectors of the modular cables and an exit for the hardwired 24-pin ATX cable. The hole where the ATX cable comes out from is covered by a flexible rubber gasket, which creates a very high quality feel. There are fifteen connectors; four for the fan power cables, four for the PCIe cables, one for the CPU 12V cable, five for the SATA and Molex cables and finally one for the OCK bracket connector.

The OCK bracket is a simple switch which allows the user to choose between a four 12V rail OCP mode and a single 70A rail mode. For those who do not which to install the PCI bracket, the power supply defaults to its standard four rail mode without anything connected. If you still want to not use the bracket but go with a single rail mode, Be Quiet! includes a jumper which forces the unit to permanently operate under single 12V mode.

A look inside the Dark Power Pro 10 850W

 Cooling fan

We found a similar Silent Wings P10 fan as we did in the 650W version of the power supply, however the part number and specifications of the fans slightly differ. The fan is still 135mm wide and features the same FDB (self-lubricating bearing) and ribbed blades as the HF18 (1800RPM) model found in the 650W version, but the XF20 version appears capable of rotating as fast as 2000RPM; a mere 200RPM more.


Despite the very similar cooling fan, the insides of the Dark Power Pro 10 850W power supply are entirely different than those of the 650W version. The design and OEM behind the 650W version was Fortron-Source (also known as FSP), yet the 850W version clearly is of Seasonic design. This explains the higher 80Plus certification of the more powerful models of the series, as well as the different performance specifications and ratings. Although this is the standard platform that Seasonic is using for many of their high performance designs, including their own, Be Quiet! modified it to include the OCK capability and hardwired the main ATX cable.

Filtering stage 

The A/C receptacle itself sports a line filter, yet Be Quiet! did not stop to that, adding more components onto the main PCB. The total number of components sum up to six Y capacitors, two X capacitors, three filtering chokes and a MOV; quite a bit more than the minimum recommended by the ATX design guide. The first rectification stage begins from two bridges, sandwiched together onto a stand-alone heatsink right next to the filtering stage.

 Primary stage

The active components of the APFC stage, two transistors and a diode, have been placed on their own heatsink at the edge of the unit. The passive APFC components are a short coil and two Nippon Chemi-Con KMR 390μF/420V capacitors. Then the primary inversion stage begins on the smaller heatsink next to the primary transformer, which holds four transistors, forming a high efficiency LLC full bridge topology.

 Secondary stage

Many silver heatsinks can be seen on the secondary side of the PCB, which however are not directly attached to any transistors. The transistors are at the bottom side of the PCB and these heatsinks essentially cool half of the entire PCB’s surface, the entire area which holds the secondary components, passive and active alike. Every capacitors is supplied by Nippon Chemi-Con, making this unit an all-Japanese affair.

 Rear PCB

A secondary PCB mounted horizontally across the rear of the unit holds the connectors of the modular cables. The DC to DC conversion takes place on that PCB, as well as most of the power distribution, with many thick bars being used to hold large currents. 

Test Setup

The load


In order to be able to effectively and efficiently test any computer power supply unit, we developed and constructed our own proprietary testing station. Our testing station consists of a number of power resistors and small capacitors, which in turn are connected to a RS485 electronic relay array which allow our load to be controlled through computer software alone.


USB interface and connection panel


When accuracy and speed are of critical importance, a simple multimeter or voltage meter is not sufficient for the task. To ensure the quality of our testing, an USB laboratory interface is being used to continuously monitor and record the readings of all voltage lines simultaneously. For ripple measurements, an oscilloscope is necessary and we chose the USB Instruments Stingray, the most widely used oscilloscope amongst low voltage PSU engineers and testers.


Measurement instruments


For accurate testing and repeatable results, a stable power input is also required. Thus, we are providing power to our test samples through a 3kVA VARIAC which allows us to control the input voltage of our test samples and also perform efficiency tests under both 110V AC and 230V AC input. A Lutron DW-6091 is also being used, monitoring the input voltage, real and apparent power, power factor and amperage.


The software


A power supply testing procedure would not be complete without thermal and acoustics tests. For our acoustics tests we are using a SL-5868P digital sound level meter, placed 1 meter away from the unit (DIN standard). Two PT100 sensors and their respective displays are being used to monitor the ambient temperature and the exhaust temperature of the unit.


Complete test setup during trial run



Testing results (Regulation & Ripple)





 While not necessarily much better than that of the FSP-based 650W version, the electrical performance of the Be Quiet! Dark Power Pro 10 850W power supply is excellent. The unit displayed a very tight voltage regulation of 1.2% on the 12V line, while the regulation of the minor lines is slightly inferior at about 2%. Ripple suppression is outstanding, with the power supply maintaining a maximum ripple on the 12V line of less than 22mV while under maximum stress. 

Testing results (Efficiency, Noise & Thermal)


The 80Plus Platinum is the highest efficiency certification of any commercial power supply available today and the Dark Power Pro 10 850W unit honors it by reaching an efficiency of 94.2% at 50% load while powered from a 230V A/C source. When the power source voltage drops to 110V A/C, the efficiency drops by about 1% across the entire load range, which is expected from all modern commercial switching PSU designs. This level of efficiency, albeit extremely high, was to be expected from a high quality power supply which bears the 80Plus Platinum certification.


It would appear that the company has programmed a “step-up” cooling profile in the 850W version of the Dark Power Pro 10. The power supply remains entirely silent at low loads, with the fan speeding up once the load exceeds 55% of the unit’s capacity. In between 60% and 85% load the fan is audible, even though barely. Only under maximum stress the fan of this power supply becomes clearly audible from a typical distance of 1m; however, a system capable of inducing such a load will probably be much louder than the power supply at this point.


For a power supply capable of running this quiet, the thermal performance of the Dark Power Pro 10 850W is remarkable. The temperature delta begins at 2.4°C and reaches only up to 5.2°C under maximum load, testament of the extremely high efficiency and good design of the power supply. 

Be Quiet! Dark Power Pro 10 850W Review Conclusion

Undoubtedly, the 850W version of the Dark Power Pro 10 is an excellent product. The performance of the power supply is exceptional on all fronts; the ripple suppression and voltage regulation are great, the efficiency is very high and the Dark Power Pro 10 is surprisingly cool and quiet considering its power output. When it comes to quality, it might be sufficient to simply mention that this is a Seasonic design improved upon by a German engineering company. Be Quiet! went with some of the best quality components currently available for commercial products and the assembly quality is astounding. Even the unique external appearance and feel of the Dark Power Pro 10 850W unit cry out that this is a very high quality product, if the 5 year long warranty was not enough of a proof.

Seasonic interior

Even though the power supply itself is excellent, there is a huge issue regarding Be Quiet!’s products however and that is no other than the availability of their units. Although the company is now trying to infiltrate the North American consumer markets, it is very difficult to find their products available. We could find the Dark Power Pro 10 850W power supply from Newegg for $239.99 plus shipping.

be quiet! DARK POWER PRO 10 550W

$ 149,00

be quiet! DARK POWER PRO 10 650W

$ 169,00

be quiet! DARK POWER PRO 10 750W

$ 189,00

be quiet! DARK POWER PRO 10 850W

$ 229,00

be quiet! DARK POWER PRO 10 1000W

$ 249,00

be quiet! DARK POWER PRO 10 1200W

$ 309,00

At roughly $245 shipped, we find this to be a very steep price which would pit it against some very tough competition. Still, the high quality, performance and aesthetics of the Dark Power Pro 10 850W power supply could generate a good level of sales from enthusiasts who are seeking unique and exceptional products.

External view

Legit Bottom Line: There is no argument that the Dark Power Pro 10 850W is an amazing product. The excellent all-around performance and astounding quality could entice many enthusiasts. However, the company clearly needs to improve the availability of their products in North America and their retail prices ought to be reduced in order to become competitive.