Be Quiet! Dark Power Pro 650w ATX PSU Page: 1
Introduction & Specifications
Be Quiet! Dark Power PROFounded back in 2002 by parent company Listan, Be Quiet! started life as a modest company, manufacturing items such as noise dampening mats. With one clear goal in sight: to reduce the level of noise output by the modern PC, it wasn't long until Be Quiet! decided to take on one of the biggest noise-makers of all - the power supply. While many of us, especially UK readers, will probably not have come across this slightly humorously named manufacturer until now, Be Quiet! has an extremely strong presence in the rest of Europe and indeed the world, with PSU sales figures often exceeding 30,000 units a month.
At present, Be Quiet! has two main PSU product lines, namely the Dark Power PRO and the Straight Power (no jokes please!). While the Straight Power series offers top performance with fixed cabling, the Dark Power PRO is now in its second edition, and offers modular units ranging from 450w to 1000w. Today we're going to be taking a look at the middle-road 650w  Dark Power Pro model, and the specifications taken from Be Quiet's website can be seen below:
First Class Level
Dark Power Pro is the high-quality power supply for perfectionists: powerful due to its highly-developed technology and extremely high degree of efficiency - unique in terms of service and quality.

With its cable management system (18 cables), every user is ideally set up for the future. ECASO thermal technology protects the PC components from overheating and guarantees a long service life. The special be quiet! fan technology plays a decisive role in ensuring that the award-winning brand runs quietly.

Dark Power Pro is also a big winner in a small package - it fits into any standard case.

Top level convenience, top level performance, top level quietness. Dark Power Pro provides everything you expect from a first class device.

First Class Technology
• Powerful, with 650 Watt
• Top quality components
• ECASO thermal technology preserves and protects components, and controls up to 4 case fans connected to the power adapter
• Only small amount of heat development due to extremely high efficiency of up to 88%
• Exceptionally stable due to 4 12V cables assigned to the components
• Extremely quiet due to be quiet! fan technology

First Class Connectivity
• Future-proof cable management with the highest possible degree of compatibility with all mainboards and graphic cards
• 18 cable sets, of which 16 are removable
• 2 x PCIe 6+2-pin
• EPS 6-pin server board adapter
• No adapter needed. Non-interchangeable due to intelligent connection concept

First Class Service
• 3 year full guarantee and therefore 1 year more than the legal requirement
• Service hotline +49 40 736 76 86 - 44 (English speaking)
• Email Support [email protected]
Probably the most impressive specification listed is the 88% efficiency rating. While this is most likely only achievable under ideal conditions (240v mains, clean voltage and high load levels), only a small fraction of PSU's tested here at Overclock3D have managed to reach 85% efficiency - so 88% would be a new all-time record.
The Dark Power PRO also comes with a 3 year "full" warranty. While the website doesn't explicitly state what kind of warranty this is (return to base for repair, or swap-out), the inclusion of an English speaking service hotline and easily accessible support email address certainly makes it easy to arrange an RMA of your unit should it develop a fault.
Be Quiet! Dark Power Pro 650w Specs
A quick look at the specifications sticker on the side of the PSU reveals the distribution of power around the unit. Keeping in mind that we're looking at the 650w version here, the unit features a total of four +12v rails capable of delivering 20 amps each, with a maximum load across all rails of 52amps. The +3.3v and +5v rails are equally well equipped with 26amps and 30amps respectively.
There is no mention of peak power output on the unit or in the specifications, but after speaking with Be Quiet! we have been told that it is 680w.
Overall the specifications are actually quite respectable, considering the capacity of the rails actually exceeds that of a recently reviewed 700w unit here on Overclock3D.
Now that we've got the boring stuff out of the way, let's see what the Dark Power Pro has in store for us in other areas...

Be Quiet! Dark Power Pro 650w ATX PSU Page: 2
When it comes to PSU's in the lower wattage ranges many manufacturers try and skimp on things such as packaging to keep the cost of the units as low as possible. The general consensus being that if you're in the market for a sub-800w PSU, then you're most likely looking for the best value available. However, often forgotten are the people that know they don't need a 1kw PSU to power their single-GPU mid-range setup, but do indeed want a PSU that has the special touches of the high-end models.
It looks like Be Quiet! are catering for just those people...
Be Quiet! Dark Power Pro 650w Box Front Ne Quiet! Dark Power Pro 650w Box Back
Be Quiet! Dark Power Pro Specs Be Quiet! Dark Power Pro 650w Specs
The Dark Power PRO comes in a rather slim yet long box complete with a carrying handle. The overall theme of the packaging is simplistic and (would you believe it) dark with the predominant colour being black. The front of the outer-box keeps clutter to a minimum with the Be Quiet! logo being tucked away in the bottom left hand corner and a grey gradient stripe over to the right that features a set of glowing cat eyes and the wattage rating of the unit.
Around the back of the packaging is an extensive list of specifications including details of the unit in a total of four languages, a power output chart and a diagram that details the length of each modular cable included in the box. Below this we are also provided with a picture of the unit from two angles and a string of award logo's from various international tech websites.
Be Quiet! Dark Power Pro 650w Box Open Be Quiet! Dark Power Pro 650w Box Open
An easily missed feature of the packaging is the velcro flap at the front of the box that when lifted, gives a teasing view of the shiny PSU contained within.
Be Quiet! Dark Power Pro 650w Box Open Be Quiet! Dark Power Pro 650w Accessories Open
Moving on to the inner-box, we can see that Be Quiet! has managed to keep things extremely tidy, using three small accessory boxes to keep sharp objects such as mains plugs separate from the PSU. However, while it would certainly take one hell of a rough delivery to cause any damage to the Dark Power Pro, I can't help but feel that the unit should have maybe been placed inside a clear plastic bag to prevent any hairline scratches from the cardboard separators devirginizing its reflective paintwork.
Be Quiet! Dark Power Pro 650w Accessories Be Quiet! Dark Power Pro 650w Accessories
Included in the box are the following items:
16x Modular cables
7x Velcro cable ties
4x Black thumbscrews
4x ATX Screws
6x Cable ties
1x Mains power cable
All things considered, not a bad bundle of extras, and certainly plenty of things to promote tidy cabling inside your PC.
The appearance of the Dark Power PRO further enforces that Be Quiet! do not believe that their low-wattage units should be stripped of luxury's. Featuring a very sexy black chrome electroplated finish that resembles a high quality paint job, the unit looks simply awesome. It's just a shame that the unit wont be visible inside most peoples PC's.
Be Quiet! Dark Power Pro Unit Top Be Quiet! Dark Power Pro Unit Rear
Be Quiet! Dark Power PRO 120mm Fan Be Quiet! Dark Power Pro Reflective
Being a PSU cooled by a 120mm fan, the Dark Power PRO is kitted out with a honeycomb grill at the back of the unit. The meshing is actually quite large and should allow heated air to exit the unit without any restrictions. Both the power plug and switch are neatly tucked into a corner, but there's no sign of a status LED often found on the higher-end "flashy" PSU's.
Be Quiet! Dark Power Pro 650w Side
Rather than spoiling the sides of the unit with specification stickers, Be Quiet! has decided to place the sticker at the top. This has the advantage of not covering over the side of the power supply you are likely to see once it is installed inside a windowed PC case. As we can see from the image above, the side of the unit is also embossed with the Be Quiet! logo.
Be Quiet! Dark Power Pro Front Modular Be Quiet! Dark Power Pro Front Modular
Around the front of the unit we can see the Dark Power PRO's modular system with a total of 13 colour coded connectors.  More information on the connectors and modular cabling system can be found over the next page...

Be Quiet! Dark Power Pro 650w ATX PSU Page: 3
Internal Components
While the weight and size of a PSU can often give us a rough idea of how the unit is likely to perform, many manufacturers are now turning to newer and more efficient methods of manufacture, resulting in smaller and often lighter power supply units. However, by looking inside the Dark Power PRO we should be able to identify some of the components used and get a good feel for the overall build quality of the unit.
Be Quiet! Dark Power Pro Inside Be Quiet! Dark Power Pro Inside
Despite having to fit a rather bulky modular connector backplane inside the unit, Be Quiet! have managed to keep everything quite neat and tidy. All cables entering the unit are bunched together with cable ties, and there are minimal cables soldered to the modular connector circuit. Cooling of the mosfets is provided by three black aluminium arched heatsinks that span the length of the unit.
Be Quiet! Dark Power Pro Caps Be Quiet! Dark Power Pro Transformer
Be Quiet! Dark Power Pro Choke Be Quiet! Dark Power Pro Fan Controller
As we'd expect from a 650w unit, the Dark Power PRO features a single capacitor (top left). The capacitor is manufactured by Strategic Polymer Sciences (SPS) and is rated at 420v / 470uf with a maximum operational temperature of 85°C. While many manufacturers use caps capable of 105°C in their PSU's, the efficiency of the Dark Power PRO should ensure that the unit never gets anywhere near this temperature.
Also pictured above (top-right, bottom-left) are the two transformers used within the unit. In normal PSU configurations the larger of the two transformers is used to power the +12v rails, while the smaller is often used for +3.3v and +5.0v rails.
Finally, pictured bottom-right is a large heatsink attached to the units fan controller. While most PSU's we've tested previously at OC3D use PWM to control low wattage fans, it would almost seem that Be Quiet! have opted for a different fan control method which generates  enough heat to necessitate dedicated cooling.
Be Quiet! Dark Power Pro Fan
The 120mm fan used inside the Dark Power PRO is manufactured by Protechnic Electric and has a model number of MGT12012LR-A25. As we can see from the specifications below, the fan is able to push a reasonable 61CFM through the PSU with a noise output of 31dBA. These figures combined with a heat based fan control should result in an extremely quiet unit.
Model: MGT12012LR-A25
Dimensions (mm): 120x120x25
Airflow (CFM): 61
Speed 1800 RPM
Noise (dBA): 31
Cables & Connectors
While most manufacturers tend to hard-wire the ATX and 4/8-Pin CPU cables into their modular PSU's, Be Quiet! have decided to only hard-wire the 24-Pin ATX connector. This may seem slightly strange at first, but as the unit supports both P4-12v, P8 and EPS 6-Pin (Server style) motherboard connectors it helps to cut down on additional cable clutter.
Be Quiet! Dark Power PRO Modular Be Quiet! Dark Power PRO Modular Backplane
To ensure that no mistakes are made during installation, Be Quiet! has colour coded every connector on the unit. This combined with the physically different size of each connector should help prevent graphics cards and motherboards from get fried by the incorrect insertion of the PCI-E cables into the 8-Pin motherboard connector.
Be Quiet! Dark Power Pro Cables
Included in the box are no less than 16 modular cables. Granted that four of these are solely for powering 3-Pin style fans, but the remaining cables are all fully sleeved in black mesh and are each accompanied with their own paper tag that explains what the cable is for and how it should be connected. A full list of the included cables can be seen below:
1 x cable for peripherals 600+150+150+150+150mm( 2xSATA / 2xHDD / 1xFDD )
1 x cable for peripherals 600+150+150+150mm ( 4 x HDD )
1 x cable for SATA connector 600mm+100+100+100(4 x SATA) include 3.3V
2 x cable for PCIe connector 600mm with 8pin to 6+2pin
1 x cable for P8 connector ( 8 pins ) 600mm
1 x cable for P4 connector ( 4pin ) 600mm
1 x cable for Motherboard ( Molex 4pin ) 600mm
1 x cable for mainbord ( Dualboard ) EPS 6pin 600mm
4 x cable for case fans ( controlled by PSU ) 700mm ( 1 x Molex / 1 x 3pin )
1 x cable for peripherals 500mm ( 1x HDD )
2 x cable for SATA 500mm ( 1 x SATA )
Be Quiet! Dark Power PRO HDD Connectors Be Quiet! Dark Power PRO PCI-E Cables
Be Quiet! Dark Power PRO EPS Connector Be Quiet! Dark Power PRO ATX
The latest graphics cards are well supported  on the Dark Power Pro, with the unit providing two 8-Pin PCI-E cables. As we can see from the image above (top-right) the connectors can also be reduced down to the "older" 6-Pin standard should you not be lucky enough to own a high-end power guzzling GPU. This is also true for the ATX connector which can be converted from the latest 24-Pin standard down to 20-Pin for older motherboards by simply removing a 4-Pin connector block.

Be Quiet! Dark Power Pro 650w ATX PSU Page: 4
Load Testing

To provide our readers with the most accurate results, Overclock3D uses a custom built PSU load tester on all reviews. This not only gives much more reliable results than the testing methods employed by other sites, but also allows for all current and future review results to be compared side-by-side. The following table shows the load (in watts) that was applied to the Dark Power PRO 650w during testing.
   0%  50%  100%
 +3.3v Rail  0w  33w  66w
 +5.0v Rail  0w  100w  150w
 +12v Rail(s)  0w  200w  400w
 Total  0w  333w  616w
Be Quiet! Dark Power PRO Load Test
A common practice among some manufacturers is to "over-volt" the rails on their PSU's. This often leads end-users to believe that they have purchased a high quality PSU just because it can maintain voltages above the rated outputs (3.33v, 5.00v & 12.00v), when in reality the manufacturer has simply set the idle voltages as high as possible just to compensate for fluctuation under load.
From the graphs above, it is clear to see that Be Quiet! is not one of this companies. With idle voltages almost exactly on their ideal levels across and very little fluctuation under full load, the Dark Power PRO performs just how a high quality PSU should.
Efficiency Results
Efficiency tests are performed by measuring the wattage consumed by the power supply at the mains (Mains Draw) against the power consumed by the OC3D power supply stress tester (PSU Load). These results may not be 100% accurate, but have proven to be extremely close to results obtained from professional equipment.
Be Quiet! Dark Power PRO Efficiency
As we can see from the upward slant of the line graph above, the efficiency of the Dark Power PRO improves as the load increases. Be Quiet! state that the unit is able to deliver up to 88% efficiency, and the results obtained from our own tests certainly suggest that is able to come extremely close to that figure.

Temperature vs Fan Speed
As with all components in the modern computer system, the performance of a PSU can be directly affected by heat. Excess heat inside the PSU can easily have a negative effect of the maximum power output of the unit and lead to voltage instability. For this reason, Overclock3D includes temperature recordings taken from the PSU's exhaust using a thermal probe to highlight any potential issues that the PSU might have obtaining its rated output.
Be Quiet! Temperature vs Fan
Under normal circumstances we'd also use a sound meter to record the dBA noise level output by the fan. However, the Dark Power PRO was so damn quiet it was simply impossible to take a reading from the PSU without the low-level ambient noise affecting the results. Even with the voltage of the cooling fan inside the unit ramping up from 4.66v to 10.97v at full load, the unit was barely audible. I can say without a shadow of doubt in my mind that this is one of, if not THE most silent PSU ever tested here at Overclock3D.

Be Quiet! Dark Power Pro 650w ATX PSU Page: 5
Be Quiet! Dark Power PROBeing a fairly new contender in the UK PSU market, the Dark Power PRO is up against some stiff competition. However, while most units from competitors are able to deliver fairly solid voltages and good overall performance, the 87% efficiency and insanely quiet operation of the Dark Power PRO puts it into a league of its own.
Unfortunately the cost of being in this league does seem to come with quite a high price tag, and at £99.88 for the 650w version over at, the unit clearly isn't aimed at those of us who are looking to save a few quid by avoiding the 1kw monster units.
However, saying that; the Dark Power Pro 650w does fill a hole in the market quite nicely: While most manufacturers are aiming their lower-wattage units at the budget market, and stripping the units of everything but the bare essentials, Be Quiet! have produced a range of PSU's that have consistent high quality with all the trimmings regardless of output wattage. This makes the Dark Power PRO series perfect for those of us intelligent to know that their single-GPU PC setup isn't going to consume anything more than 500w of power, but are still willing to pay that little bit (?) extra for all the goodness normally only found on other manufacturers flagship models.
The Good
• Ultra-high efficiency @ almost 87%.
• Very stable voltages with no "over-volting".
• Sexy electroplated finish.
• One of the most silent units we've heard in a long time.
• Excellent modular cable system.
• Package and accessories make it feel worth every penny
The Mediocre
• Nothing to report
The Bad
• Its pricey. PSU connoisseurs need only apply.
Overclock3D Editors Choice Award
Thanks to Be Quiet! for sending over the Dark Power PRO. Discuss this review in our forums.