be quiet! Dark Power 12 (850W) Power Supply Review

If there’s one thing we constantly recommend to our community regarding power supplies, it’s never to go cheap and nasty! – Yes, unfortunately, good PSUs do cost more, but at the end of the day, a good model can not only save you money from the wall socket, but it can also last you several PC builds. Well, depending on how often you get the urge or finances to upgrade. Therefore, when it comes to be quiet! In all honestly, their power supplies are not often cheap, but in terms of build quality and features, they’re undoubtedly one of the best brands around!

As such, when the newly released Dark Power 12 (850W) arrived, you can be more than sure we were anxious to check it out and see what they’d managed to cook up this time!

be quiet! Dark Power 12 (850W)

The Dark Power 12 certainly seems to represent a very impressive design in terms of specifications and features. Available in 750w, 850w, and 1000w variants, for this review we will be concentrating on the 850-watt model, although we did want to make you aware that other options are available depending on how much power your build requires!

Coming with a fully-modular cable design and a stonkingly impressive 80-Plus Titanium efficiency rating, the be quiet! Dark Power 12 definitely looks to be a fantastic choice for the savvy PSU shopper!

What Does be quiet! Have to Say?

“Dark Power 12 850W is certified with 80 PLUS Titanium and an energy efficiency rating of up to 95.6%. This provides lots of benefits for your high-end system, including less power consumption and an overall cooler and quieter operation. The standby drain is below 0.1 watts.”

Features

• 80 PLUS Titanium efficiency (up to 95.6%)
• Patented frameless Silent Wings fan for virtually inaudible operation
• Revolutionary full-mesh PSU front with redesigned funnel shape air inlet upholds the high air circulation abilities
• Overclocking key switches between four 12V rails and one massive 12V rail
• Modular cable management for maximum convenience
• Active Rectifier + full bridge LLC technology provides unmatched signal stability and extremely high power efficiency
• Ten-year manufacturer’s warranty

Specifications

For more detailed specifications, please visit the official product page via the link here!

Connections

Coming as a fully-modular power supply, the be quiet! Dark Power 12 is provided with plenty of cables to hook up even the most elaborate of systems. If you do, however, need confirmation, you can check out the supplied cabling list below.

Packaging

The packaging is instantly recognizable as a be quiet! product with the black and silver highlights. In terms of presentation through, its certainly off to an excellent start at the front with a nice clear image of the power supply provided.

Unfortunately, when you turn to the rear, things get a little more drab and mundane. The information provided here is small, it poorly utilizes the available area, and quite frankly, it doesn’t tell you everything you might need to know about this PSU (such as what cables you get). My presumption is that be quiet! has provided that QR code to take you to the product website, but in all honesty, the box work and details could’ve been significantly improved for not much more effort.

Although not a point we often get to raise with power supplies, the internal components’ quality is truly excellent. Opening up the box, this really looks like a high-quality professional product and, while the exterior packaging might be a little disappointing, you forget all about that once you’re inside!

Accessories

In terms of accessories, be quiet! has you covered with everything you could possibly need right out of the box including some pretty useful additions.

Without a doubt, one of the most interesting inclusions is the overclocking performance adaptor which can be mounted directly onto a spare external (and empty) PCI-E mounting bracket. With one simply flick of the switch, you can tell your Dark Power 12 to keep the power coming because, if it’s a hefty overclock, you’re probably going to need it!

The product manual is of a very nice quality, albeit the information provided within is somewhat boring unless you really care about the power supplies specifications (we do!). Finally, we should also note that the modular cables are contained within a rather fancy cardboard box. While the quality is certainly good, there is a part of me that wonders whether a canvas bag (as you often see from other brands) would’ve ultimately have been far more practical. I mean, it’s great to have somewhere to keep your spare cables for another day or upgrade, but at least a bag can usually cram in some free cupboard space!

A Closer Look

Out of the packaging, the be quiet! Dark Power 12 certainly seems to live up to its name with an impressively stark black representation with silver highlights to the product branding.

In terms of that branding, it is, generally speaking, quite understated. I mean, yes, it’s rather larger, but it fits in well with the overall ethos this power supply presents and be quiet! has even gone to the trouble of plastic protective stickers over it so it won’t be damaged/scratched during transit or installation.

The top of the power supply greets you with a huge vented area underneath which sits a be quiet! own SilentWings cooling fan. The vents are set in almost a grid pattern giving you a hint of what’s going on underneath while not actually revealing much that might offend the eye.

The only mild downside is that the vent gaps are so tight that you can barely make out the be quiet! logo to the center of the fan. From a visual standpoint, it would’ve perhaps have been better to set this logo onto the grid, but then again, that would’ve impeded airflow and, as we know by the listed features already, this design is built for efficiency and performance.

The main ventilation area of the power supply is fantastically set with practically the entire available area open for airflow. With the vertical bars as well, for an area of the power supply that’s usually a little boring, be quiet! has definitely put some effort into making this look exceptionally professional.

As a fully-modular power supply, the cable input bank can be found to the other side of the power supply. This is definitely a great design in terms of ease of use as all ports have been specifically itemized to ensure you put the right cable in the right hole!

When fully loaded, space is quite limited and you might find removing cables a little tricky, but overall, it’s neat, tidy, and certainly offers you some great options for cable management.

Cabling

Every cable is itemized, like the input bank, to ensure that you connect it to the right component. In addition, with each cable coming with an individual Velcro strap, management and storage has been made vastly easier and tidier. Specifically, when compared to the plastic ties you usually find in most other PSU models.

Internals – A Look Inside!

Getting inside the be quiet! Dark Power 12, everything is well presented with all of the major components seemingly well organized and spaced. This should, be proxy, allow for good levels of airflow meaning that the fan doesn’t have to work as hard meaning lower-noise output.

A closer look at the capacitors would confirm be quiet!’s claim that the Dark Power 12 utilizes ‘100% Japanese’ designs with 105C rated models from ‘Nippon Chemi-con’ clearly visible (and also on the smaller capacitors). In terms of quality power supplies, put simply, this is without a doubt some of the best options around and, whenever you see these, you know a PSU has a fantastic chance of storming its tests!

Overall Thoughts!

Sleek, stylish, and professional. The be quiet! Dark Power 12 looks to be a fantastic design both internally and externally. There is though, and of course, the small matter of how this actually performs when operating. So, without further a do, let’s get this strapped onto our test bench and see how it does!

Methodology & Testing

At eTeknix we take the power supply testing procedure very seriously and have invested a lot of resources into acquiring the appropriate testing equipment. For all power supply reviews, we test the power supplies with dedicated power supply testing equipment. This means we are able to get the most accurate results from our testing as opposed to using software benchmarks (such as OCCT) or multi-meter readouts which are broadly inaccurate.

Testing Hardware

• Sunmoon SM-5500ATE Active Load Tester (1200W rated)
• Stingray DS1M12 USB Oscilloscope
• Voltcraft DT-10L laser tachometer

What the eTeknix Test Procedure Involves

• Testing each power supply at 20/40/60/80/100% load (with load balanced across all rails) and measuring PFC (power factor correction), efficiency (actual power divided by power “pulled at the wall”) and voltage regulation (deviance from expected voltages of 3.3/5/12 on the main rails).
• Measuring ripple with an oscilloscope at 20/40/60/80/100% load.
• Measuring fan speed after a stabilisation period of five minutes at each load scenario using the Voltcraft DT-10L laser tachometer and a reflective strip on the fan.
• Testing each power supply’s OPP (Over Power Protection) mechanism and seeing how many watts each power supply can deliver before shutting down

Other Things to Consider

• We recognise that a single 12-volt cable can provide only 6 Amps before overheating (which corrupts voltage regulation and efficiency) and so we used an adequate number of cables for each power supply to ensure there is not efficiency loss from poor cables selection
• Our Sunmoon SM-5500ATE power supply tester is not capable of testing more than 300W on each of the 12-volt rails so where a power supply provides more than 300W on a 12-volt rail that power is distributed over multiple 12-volt rails on the load tester. For example a power supply with one 12 volt rail supplying 750 watts would be spread equally over three 12 volt rails on the load tester, a power supply with two 450W 12v rails would be spread over four 12v rails on the load tester, two 225W 12v rails for each of the 12v rails on the unit.
• We use the same time scale and horizontal millivolt scale on our oscilloscope for all ripple tests, that is a 20ms T/DIV (horizontal) and a 0.02 V/DIV (vertical) meaning the scale is from -80mV to +80mV, ATX spec dictates that the 12v rail must fall within 150mv of ripple and the 3.3/5 within 50mv so that scale allows us to include both 150 and 50mV peaks. (Some older PSU reviews use different scales which were later ditched as the visual representation they give is inadequate, in these reviews written measurements are provided only).
• Deviance is the terminology used to represent the way voltages diverge from the expected values

Voltage Regulation

To test voltage regulation we load the power supply to five different load scenarios that give an equal spread of load across every single rail. So that means 20% on all rails, 40% on all rails and so on. We then calculate the average deviance of each rail from its expected voltage. Ideally, anything of +/- 2% regulation is seen as a very good result.

Power Efficiency

Power efficiency is measured by calculating actual supplied wattage divided by the wattage drawn at the wall/plug, multiplied by 100 to give a percentage. We then compare that to the particular 80 Plus certification the company claims to see if it meets that. You can see the 80 Plus certifications below, we always test power supplies at 230v.

Power Factor Correction

Power Factor Correction is the ratio of the real power flowing to the load, to the apparent power in the circuit. The aim of PFC is to make the load circuitry that is power factor corrected appear purely resistive (apparent power equal to real power). In this case, the voltage and current are in phase and the reactive power consumption is zero. The closer the number to one the better as this allows the most efficient delivery of electrical power (Source – Wikipedia).

Ripple

Noise and Ripple can easily be measured by an oscilloscope. These show how much voltage fluctuation there is on a particular rail. We tested the rail stability of the 3.3-volt, 5-volt and 12-volt rails using an identical time and millivolt scale for all graphs. millivolt ripple is measured by the peak to peak size of the voltage curve.

The latest ATX 12 volt version 2.3 specifications state that ripple from peak to peak must be no higher than 50 millivolts for the 3.3-volt and 5-volt rails, while the 12-volt rail is allowed up to 120 millivolts peak to peak to stay within specifications. Millivolt figures are stated to the closest increment of 5 given their variability.

OPP

Power supplies often quote as having various protection mechanisms such and the most important of these is Over Power Protection. In our testing we crank up the power draw until the power supply either shuts down (meaning the OPP mechanism is present and working) or blows up (meaning it is either not present or not working). We then note the maximum power consumption before the power supply shut down, or before it blew up.

Fan Speed

When testing in a power supply laboratory it is difficult to take fan noise readings as the noise from the Sunmoon test equipment and air conditioning corrupts everything. The next best thing in our circumstances was reading off the fan speed with a tachometer to get an idea for the noise. The ambient temperature during testing held constant at 22 degrees, with 1 degree of variation. Each power supply had a consistent time period of 5 minutes to stabilise between each load scenario.

In my experience, the following general relationships apply between noise levels and fan speeds, though it can vary greatly between the type of fan used.

• Below 800 RPM – Inaudible/Silent
• 800 to 1000 RPM – Barely audible
• 1000 – 1200 RPM – Audible but still quiet
• 1200 – 1400 RPM – Moderately noisy
• 1400 – 1800 RPM – Noisy
• 1800 RPM or above – Intolerable

Efficiency

Coming as an 80-Plus Titanium rated power supply, this is, in terms of efficiency, as good as it can possibly get under current standards. Who are we to take be quiet!’s word for it though? – Alas though, if you were hoping that things would get off to a rocky start (albeit, we have no idea why) then you’re set to be disappointed… Or maybe pleasantly surprised.

Put simply, the be quiet! Dark Power 12 absolutely stormed our efficiency test and is, by a comfortable margin, 100% a Titanium power supply.

PFC (Power Factor Correction)

While the 20% load PFC score is always significantly lower than every else that follows, the big surprise here is that the result here is actually quite high. I can’t honesty recall any other power supply that managed a score this good at such a low wattage output.

This shouldn’t overshadow the fact that, as a whole, the results are excellent, but in terms of low-power requirements, the PFC is much, much, better than anything else I’ve seen from any other PSU I’ve personally encountered (and I encounter a lot of them!).

Voltage Regulation

Consistency is King for the be quiet! Dark Power 12! – While there is a little deviancy in the overall ‘perfect’ score, the results provided are still very good from the standard point that they are all so solid and similar. In a nutshell, no matter how hard you ask this PSU to work, it’s going to deliver the right amount of voltage all the time!

Ripple

Similar to everything we’ve seen before, the ripple scores provide no Achilles heel for the Dark Power 12 as not only are all the results well below the EU maximum of 50 but in the vast majority of tests, we’re only looking at single-digit results.

Admittedly, there was a mild jump seen on the 12V output at 80% load, but given that this practically halved for the test before and after, we’re willing to put this down as an aberration rather than anything to be worried about.

Over Power Protection and Max Wattage

Although strictly rated to systems requiring up to 850 watts of power, it’s never usual for a power supply to offer a little headroom above that value. When you do push things too far, however, it’s important to know that the protections are in place to turn your system off before something goes bang!

So, what happened in our test? – Well, it’s good news all around really. Not only did the OPP work perfectly, but the Dark Power 12 managed to achieve 244 watts over its rated level before it did kick in. Given that this is around 23% higher than the official wattage level, while we never recommend dipping into that, it’s nice to know that not only is it there, but it’s also standing by to reign your irresponsible usage in!

Fan Speed

As the brand name might’ve suggested to you (or at least I hope it has by now), be quiet! prides itself on making exceptionally muted products. I must admit though that I was somewhat surprised to see that this PSU did not have a hybrid function. Then again, during the tests, while the fan did consistently run, we never recorded it exceeding a speed of over 250 RPM.

Putting this in combination with that absolutely fantastic SilentWings cooling solution, the Dark Power 12 is, for all intents and purposes, as noiseless as you could wish for! Rather impressive given that this does come with a pretty hefty wattage output!

How Much Does it Cost?

Of the three models set to be released from this range, be quiet! has confirmed the following MSRP prices:

• $199.90 / £205.99 / €214.90 (750W)
• $239,90 / £239.99 / €249,90 (850W)
• $279,90 / £269.99 / €279,90 (1000W)

So, sticking with the 850-watt model here, as per our review, while £239.99 certainly isn’t cheap, you do, of course, have to remember three key factors. Firstly, this is, without a doubt, a premium design. Secondly, this provides 850 watts of power with a fully-legitimate 80-Plus Titanium efficiency rating. Thirdly, with that 10-year warranty, you can easily look at this power supply as a long term investment rather than as an individual purchase!

Performance

It’s usually at this point in the review where I might list a bunch of good things and then perhaps pick out one or two individual concerns. With the be quiet! Dark Power 12, however, we can’t do that. Why? – Well, because as clearly visible throughout all of our testing, this power supply is just fantastic!

Every result provided was entirely acceptable, as good as, or better than we expected. The highlights, however, undoubtedly have to go to the amazing efficiency performance, it’s remarkably low ripple noise, and, of course, that practically silent fan operation.

Practicality & Functionality

There is absolutely nothing I can think of that would limit you from using this power supply within your system. Well, expect how much power you need presuming 850w isn’t enough. An output that, by my thinking, is more than enough for the vast majority of gaming systems. It’s fully-modular, meaning you don’t have to utilize the cables you don’t need, the cables themselves are nice and flexible allowing for good management, and the PSU itself runs so quietly I promise you that you will not hear this at all unless you’re really trying to pick it out!

Should I Buy One?

The only real caveat the be quiet! Dark Power 12 has is that, when compared to a lot of other models currently on the market, it isn’t cheap. As we said right at the beginning of this review, however, going cheap on power supplies rarely rewards you and, given the fantastic level of performance this PSU provides on practically every conceivable level, if you can afford the expense, you’d be hard put to find a better performing power supply than this!