Be Quiet! is a German manufacturer that mainly produces PC cases, power supply units (PSUs), and cooling-related products. As the company's name suggests, their products are designed with quiet operation primarily in mind. The company is no stranger to the North American markets, slowly but steadily increasing its presence over the last few years. Their commitment to continue to increase their presence in the United States became apparent with the recent founding of a US-based service center in California for seamless after-sales support.

Be Quiet!’s main market focus currently lies with PC PSUs, with the company offering more than three dozen different designs split under eight different series. Although most of their products are targeted toward mainstream users, and are consequently designed to be balanced between cost-effectiveness and performance, the company is broadening its product ranges every few months, offering some impressive high-end designs to round out their product lineups.

In today’s review, we are taking a look at the pinnacle of Be Quiet!’s PSU design efforts, the Dark Power Pro 12 1500W (BN647). The Dark Power Pro has a long list of features, the highlights of which are the 80Plus Titanium efficiency rating, the patented Silent Wings cooling fan, and the monstrous 1500 Watts continuous (and 1600 Watts peak) output, which are balanced by a colossal $450 price tag. Be Quiet! clearly is aiming to take on the halo products of the few renowned manufacturers that released >1.5 kW products in the past couple of years, setting a very high bar for our expectations.  

Packaging and Bundle

Be Quiet! supplies the Dark Power Pro 12 1500W PSU in a large, sturdy, and externally aesthetically minimalistic cardboard box. Despite its simplistic appearance, the packaging is very sturdy and of high quality. Practically nothing is printed at the front of the box but plenty of details can be found on the sides and rear.

A rich bundle can be found inside the box, as expected from a halo product such as this. Inside the box we found the standard AC power cable, four typical mounting screws and four thumbscrews for the user to select whichever they prefer, ten cable straps, a few cable ties, wire combs, and a PCI slot switch. The PCI slot switch can be used to turn the “overclocking” mode on and off. When off, the PSU has multiple virtual 12V rails, monitoring them for overcurrent individually. When overclocking mode is on, it monitors the entire 12V line as a single rail, preventing the PSU from shutting down when a single connector draws a little bit too much power. The catch is that the latter mode cannot discern single-wire critical faults and such a fault could lead to a massive current over a single wire, irreversibly damaging it.

The Dark Power Pro 12 is a fully modular design, allowing for the removal of every DC power cable, including the 24-pin ATX connector. All of the cables are black, with black connectors and individually sleeved wires. We also found not one but two floppy disk power adapters inside the packaging, an amusing but very odd thing for such a product in 2021.

The Be Quiet! Dark Power Pro 12 1500W PSU

External Appearance

The Be Quiet! Dark Power Pro 12 is visually imposing, featuring a unique layered chassis. The exterior is almost entirely black, with very smooth brushed surfaces and sharp edges. The chassis is very long, measuring 200 mm deep, which makes it incompatible with a large number of smaller cases, but this shouldn't be an issue for the kind of large computers where you'll need (and be able to cool) 1kW to begin with.

Chrome fonts form the series and company logos on one side of the unit. The other side is covered by a sticker with the unit's electrical specifications and certifications. The top side of the chassis is almost perfectly clean, with the small exception of the warranty sticker. A massive on/off switch can be seen at the rear side of the unit, right below the IEC C19 connector, which was required considering the high current draw when the PSU needs to be powered from a 115V AC source.

The front side of the Dark Power Pro 12 is filled to the brim with the connectors for the modular cables. Be Quiet! is using a straight 5-pin connector for the SATA/Molex cables, dual row 10-pin cables for the CPU cables, and dual row 12-pin connectors for the PCIe cables. The ATX cable connects to two connectors at the PSU's side, a large 20-pin connector, and a second 8-pin connector. The printed legend indicates which virtual 12 V rail corresponds to every connector. Even though each group consists of physically identical connectors, users should be careful not to connect the cables randomly but as recommended in the manual, because the default mode of the Dark Power Pro 12 is with multiple 12V OCP rails, meaning that the PSU will shut down if the load is improperly balanced.

Internal Design

We usually find Be Quiet! using their own fans to cool their PSUs, and the Dark Power Pro 12 is no exception, using a Silent Wings 135 mm fan under the finger guard. The only difference here is that the Dark Power Pro 12 is using a frameless version of the fan. This design supposedly reduces the intensity of the vibrations and increases airflow, but there is a downside to it – if the fan ever fails, finding a replacement will be a challenge for anyone but the manufacturer. The maximum speed of the 135 mm fluid-dynamic bearing (FDB) fan is 2600 RPM, an extremely high speed for a fan of this size.

Be Quiet! employs several OEMs for the design and production of their PSUs. The OEM behind the creation of the Dark Power Pro 12 is Channel-Well Technologies, or CWT. Many experienced enthusiasts might have guessed that sooner by the presence of the multiple virtual 12V lines, a design tactic frequently employed on their platforms.

The platform that the Dark Power Pro 12 can be a very interesting discussion and research topic. It is not a fully digital platform, but rather it's a hybrid. Specifically, it uses digital controllers on the critical parts and analog controllers on the secondary rails that derive from DC-to-DC converters.

Diving deeper, there was nothing special regarding the filtering stage, which comprises a total of six Y capacitors, two X capacitors, and two filtering inductors leading to a dual input rectifying bridge configuration. The bridges do not have their own heatsink but are attached to a large heatsink that holds most of the active primary side components. There are not one, not two, but three APFC capacitors to cope with the massive power requirements of the unit. Two capacitors are made by Nichicon and one is supplied by Nippon Chemi-Con.

Four transistors form a full-bridge inversion topology at the primary side of the unit. There are two transformers but a single output, most likely because there was no room for a single transformer that was powerful enough – or a single transformer powerful enough that could fit in this design was too expensive. The twelve MOSFETs that generate the 12V rail on the secondary side are all attached on vertical daughterboards with their own heatsinks.

The 3.3V and 5V lines are being generated via the DC-to-DC conversion circuits found on the vertical PCB near the front of the unit. All of the secondary lines, including the 5VSB line, are governed by an analog controller. There are numerous electrolytic and polymer capacitors to be seen in the Dark Power Pro 12. Nichicon, Rubycon, and Nippon Chemi-Con supply the electrolytic capacitors, while FPCAP and United Chemi-Con supply all of the polymer capacitors. And although five different capacitor suppliers are involved in the creation of this specific PSU, all of them are renowned for their high-quality products.

Cold Test Results (~22°C Ambient)

For the testing of PSUs, we are using high precision electronic loads with a maximum power draw of 2700 Watts, a Rigol DS5042M 40 MHz oscilloscope, an Extech 380803 power analyzer, two high precision UNI-T UT-325 digital thermometers, an Extech HD600 SPL meter, a self-designed hotbox and various other bits and parts. For a thorough explanation of our testing methodology and more details on our equipment, please refer to our How We Test PSUs - 2014 Pipeline post.

The “Overclocking mode” of the PSU that combines all virtual 12 V rails into a single 12 V rail was active throughout our testing, with the exception of the preliminary OCP tests that we perform routinely, which the Dark Power Pro 12 passed without issues.

The efficiency of the Be Quiet! Dark Power Pro 12 1500W PSU is very high but not as high as we would have liked it to be. Although it meets the 80Plus Titanium certification requirements while the unit is powered from a 115 VAC source, it does so only only barely, with an average nominal load range (20% to 100% of the unit's capacity) efficiency of just 92.3%. When powered from a 230 VAC source, in our testing the Dark Power Pro 12 1500W PSU does not even get near the 80Plus Titanium certification requirements.

As the load increases beyond 1000 Watts, the thermal control circuitry will start increasing the speed of the fan at an exponential rate. That is a very reasonable design approach, as a gaming PC drawing more than 1000 Watts isn't going to be able to remain quiet anyhow. Especially as the noise from the fans of power-hungry components will most definitely overshadow the single 135 mm fan of the PSU.

Hot Test Results (~45°C Ambient)

Switching to hot box testing, as expected, the Dark Power Pro 12 1500W PSU faces a very small efficiency drop when the ambient temperature is very high. That is because the active components of the unit are extremely efficient and resilient to thermal stressing, otherwise it would be practically impossible to output this kind of power with such a platform at all. The average efficiency reduction is 0.6%, with a marginally higher drop of 0.7% at 100% load.

Despite the relatively high conversion efficiency of the Dark Power Pro 12, the platform still needs to cope with very high raw thermal losses inside a very hot operating environment. Thermally, the Dark Power Pro 12 performed better than what we initially hoped for. Although the internal temperatures of the unit are always high – going higher than 70°C on the major active components – the temperature is not greatly affected in relation to the unit’s load. As such, even at maximum load, the Dark Power Pro 12 still copes well with the thermal losses and keeps on operating seamlessly.

The key element behind the Dark Power Pro 12’s ability to withstand such thermal losses in such a hot environment is the Silent Wings cooling fan that, under these operating conditions, is anything but silent. The thermal control circuitry of the PSU is reading the very high temperature and reacts to it by putting the fan to work, boosting its speed up to 100% before the load is even 50% of the unit’s rated capacity. The result of this approach may be a very loud PSU but, apparently, Be Quiet!’s engineers knew better than sacrificing reliability over acoustics.

Power Supply Quality

As part of our testing, we also check output parameters are within specifications, as well as voltage ripple and line noise.

The electrical performance of the Dark Power Pro 12 is exceptional, and is exactly what we'd expect from a flagship product such as this. Our instruments recorded a maximum ripple of 30 mV on the combined 12V line - a mere quarter of the 120 mV recommended design limit on a unit that outputs 1.5 kW. The filtering on the 3.3V and 5V lines is very good but not as impressive, with 16 mV and 18 mV on the 3.3V and 5V lines respectively. Voltage regulation is exceptional on the 12V line, holding at 0.6% across the entire nominal load range. The 3.3V and 5V lines are less strictly regulated, at about 1.2% according to our readings.

Conclusion

Be Quiet! obviously designed and marketed the Dark Power Pro 12 as a prime example of their brand name – a halo product, a testament of the company’s ability to design and produce top-tier units. And while the company isn't looking to name competitors, Be Quiet! is clearly taking a shot at Corsair and their fully digital AX1600i, a design that many (ourselves included) consider to be the best consumer PSU ever made. To go against the AX1600i is a very ambitious and respectable move, especially considering that only a handful of companies have ever tried.

As a result, the 80Plus Titanium certified Dark Power Pro 12 1500W PSU is very impressive on paper. Yet our closer inspection and testing revealed that it is not quite on par with the fully digital AX1600i, both technologically and otherwise.

The electrical performance of the Dark Power Pro 12 is excellent. Yet it still feels inadequate in some ways. We would have been very impressed by the power quality of the Dark Power Pro 12 were it was a middle to high tier product, but as a flagship product, there's no reason to expect anything but the best from such a PSU. The filtering of the voltage lines is excellent and they are very well regulated, especially when taking the very high 1500 Watt power output into account, but it still is not on par with the ludicrous performance figures that a fully digital platform can deliver. The digital-analog hybrid platform from CWT also has other electrical performance limitations, which are apparent on the power quality of the analogically controlled minor lines and the inability to reach very high-efficiency figures when powered from a 230 VAC source.

Still, it is worthwhile to point out that this platform is the only high power output platform currently available in the North American and European markets that offers multiple virtual 12V rails. Whether the presence of multiple rails is a good thing or not is a topic for debate – multiple rails are safer, as the protection circuitry will not allow a single cable or connector to draw the entirely of the unit’s power output and be damaged. But, on the other hand, balancing the load between the rails is necessary. To that end, we would strongly suggest users keep the power supply in its default mode and only switch overclocking mode on (and let the Dark Power Pro 12 monitor its 12V output as a single power rail) if they face trouble powering a very power-hungry device from a single connector.

The thermal and acoustics performance of the Dark Power Pro 12 are both better than we initially expected from such a powerful unit, even from one bearing an 80Plus Titanium efficiency certification. Under normal operating circumstances, the Dark Power Pro 12 should remain almost dead silent, as it takes a very high load for the thermal control circuitry to even bother speeding up the cooling fan. Otherwise, if the unit finds itself operating in an adverse environment and/or is very heavily loaded, it will protect itself by sacrificing acoustics over reliability.

Finally, it's clear that Be Quiet! has invested a significant amount of effort in order to make the Dark Power Pro 12 aesthetically unique – a PSU that stands out from the rest at first sight but without compromising the company’s profile of elegance and subtleness. The designers developed a unique layered chassis with a brushed metallic exterior shell and an equally unique metal mesh fan cover, which makes for a product that radiates quality without being extravagant. And this high level of design quality for the Dark Power Pro 12 is not just at a superficial level; Be Quiet has used top-quality components on the inside as well, down to the least important capacitor. Fittingly, Be Quiet! backs the Dark Power Pro 12 with a 10-year manufacturer warranty.

The Dark Power Pro 12 1500W unit is a very powerful PSU, capable of driving almost anything, but also giving it a very limited market potential, especially in the current PC market where video cards are scarce and extremely expensive. It also has to take on the venerable Corsair AX1600i, the performance reference of any top-tier PSU. Only a handful of companies have even dared to try and take on the Flextronics-based AX1600i, which underscores the value in (and confidence of) Be Quiet!’s engineers for even trying. Still, the digital-analog hybrid platform from CWT cannot outperform the AX1600i in terms of performance, nor make Flextronics engineers feel uneasy at all.

The overall performance of the Dark Power Pro 12 is great, but it's just not enough to steal the crown of the best consumer PC PSU ever made. Nonetheless, Be Quiet! has a massive advantage when it comes to overall value – the Dark Power Pro 12 1500W currently retails for $450, which is half the price of Corsair’s AX1600i. So for builders who do need a 1500W+ PSU but do not care about having the best possible performance, the Dark Power Pro 12 shines in its own way as a far more economical choice.