be quiet! Dark Power Pro 10 1200 W Power Supply Review

Today we have something interesting. We have the German version of excess in Power Supply form. Previously we checked out the American version of excess in the NEX1500. Today’s unit, the be quiet! Dark Power Pro 10 1200 W is an entirely different sort of excess. It looks suspiciously like people at be quiet! are thinking about people’s needs. If this unit has performance to match its specifications I am going to be very happy indeed. Will I be happy? Will it function correctly? Will it come with a USA power cable? All that and more will be revealed!

Features and Specifications

I’m going to be going into obsessive detail in the cable sections, so I’m going to go relatively light here and use pictures for the most part. We’ll start with the box’s features list.

Yes, I realize it’s a huge picture. Tough. The fan’s MTBF is pretty epic, not sure I really believe that. Then again I haven’t seen a MTBF rating that I believe (for a single unit, MTBF is really designed for when you have a huge rack of the things running) in a long time. Balanced fan is very nice though!  Four rails is also nice to see, that’s a good safety measure to have in a unit this large. There are a number of units using LLC full bridge primaries and DC-DC secondaries, so I’m not sure how innovative it is at this point. On the other hand it is the latest and most efficient setup going. The connectors list looks epic, but we’ll get to that in a bit. I’m a huge fan of modular cables and cable management, it makes me happy. I haven’t seen PSU controlled case fans in a while, I’ll be curious to see what be quiet!’s take is on the idea. I’m a big fan of five year warranties and German QC, as well as full protections. All told, it’s a nice list.

Here’s the cables:

That cable selection ought to cover things, don’t you think? It might be just a touch excessive maybe. Of course it’s also exactly the kind of excess I like, someone put a lot of thought into this cable setup. We’ll go through them in detail in a bit.

Lastly, a power output chart:

The rail setup is interesting, I’ll try to figure out which cables go where, we’ll see how doable that is. 3.3 V and 5 V get a fairly standard 25 A each and 150 W combined, while we get 99 A for the 12 V bits. Interestingly there are peak numbers as well, generally I avoid peak numbers as it’s a very vague kind of thing. Not so on this unit! be quiet! provided a time spec for the peak numbers, you get 1300 W for 20 ms. Enough to survive a transient load without shutting down. Is this actually useful? I don’t know. I do appreciate how specific this chart is though, it’s refreshing.

Let’s check out the box as a whole. That’s right, this is a holistic review.

Photos Part One: The Box

We saw a lot of the box before, we now get to see the handle (very nice), the front (sedate, I like it), and the end that isn’t text in foreign languages. It has CFX/SLI labels, a vaguely misleading efficiency chart (starting higher than zero annoys me), some awards, nothing spectacular really.

All together the box is… quiet. I approve. The handle is nice as it’s far from lightweight. Also worth noting is that it took somewhat of a beating between Germany and California (though less than I took making the same trip I think), that will be a good test of the packaging inside said box.

With the box open we see foam. With the foam removed we see gratuitous use of foam (perfect!), a box of cables, a fairly thick manual, more cables, and a PSU that vaguely resembles a BBQ grill. Let’s pull the PSU out and look at it.

Photos Part Two: The PSU

Note the rubber on both ends, be quiet! is serious about this “quiet” thing.

The modular output setup is very clean and vaguely industrial. The grommet on the ATX24P cable (that being the only hard-wired cable) is arguably the best I’ve ever seen. Very overkill. All the connectors are impossible to plug in incorrectly and are very well labeled. Do note that the fan connectors are rated for a total of 0.8 amps for all four. That will do a decent number of low speed or medium speed fans, but high speed jobbies may be an issue.

As usual on this sort of unit the side labels are set up so that as long as your PSU is at the rear of your case, the label will always be right side up regardless of what direction the PSU fan is facing. Of course that means that if you have a front mounted PSU it’s always upside down. Can’t win them all.

Photos Part Three: Cables

This could be a rather large section, there are a lot of cables. Actually scratch the “could be” part, it’ll be significantly larger than the normal cable section. Rather than give you a ton of a few sorts of cables, be quiet! has given you a few of a lot of different sorts. This makes a lot more sense to me. Maybe it’s because a decent chunk of my family hails from Prussia, but the German idea of high end overkill is looking awfully good to me. In any event, let’s look at the cables now.

Yes, you get three different power cables to match your requirements. The only motherboard this won’t run is one that wants two EPS12V (8P) connectors and one ATX12V (4P) connector. Those are quite rare though, so don’t worry about it.

We get three cables with two 6+2P plugs, one cable with two 6+2P, and one 6P. All four cables can be plugged in at once, giving you plenty of plugs.

Each large cable has four SATA plugs, the little single plug cable has a single plug.

One of the two multi-plug Molex cables has two Molex and one FDD, the other has three Molex. You also get two single-plug Molex cables, a long one with a blue connector and a shorter one with a black connector.

We also get a cable with two SATA plugs, two Molex plugs and one FDD plug. That one cable will probably run most systems.

We only get five plugs for the SATA/Molex cables, so some thought will need to go into which you plug in.

The power cable in this box is German, likely because this unit came directly from Germany and is a German market model. If you buy it in the USA it’ll come with a USA type cable I’m sure. The accessories pack covers a lot of bases, you get a big stack of velcro cable ties, some zip ties, five (in case you lose one) black screws and five black thumbscrews. That’s complete!

The OCK bracket mounts in the rear of your case and lets you switch between four 12 V rails and one big 12 V rail. The manual is adamant that you must not flip the switch with the unit turned on. The jumper at the bottom allows you to run the unit in OCK mode without having to use the bracket. If you don’t plug anything in, you get four rail mode. Personally I don’t see this being needed, but who knows.

That was a lot of cables, let’s plug a few in and test this thing!

Load Testing Part One: Regulation

A decent load test of a PSU requires a decent load. Contrary to what some may believe, that means you need a known load that can fully stress the PSU. Computer hardware does not cut it. Worse, if the PSU fails during testing it might take out the computer hardware anyway. Commercial load testers cost a lot of money. I do not have a lot of money, so I built my own with juicy power resistors and a Toyota cylinder head. It works great. I’ll be using it to load this thing down fairly severely and will check voltages and ripple (more on that later) at various points. The down side to my tester is that the loads it can put on PSUs are fairly coarse, they go in increments of 48 W for 12 V, 50 W for 5 V and 22 W for 3.3V. Those wattages assume the PSU is putting out exactly the official rail voltage, a PSU putting out 12.24 V rather than 12 V will be at 49.9 W per step rather than 48 W. I file that under the “tough beans” category as I figure if a percent or two of load makes that much of a difference, the PSU manufacturer should have hit the voltage regulation more squarely. It does make calculating efficiency difficult at best.  However, given that the input power is read via a Kill-a-Watt, the efficiency numbers are dubious to begin with. Kill-a-Watts are not known for extreme accuracy on things with automatic power factor correction. For this reason, I am not listing the efficiency.

The ATX spec says that voltage regulation must be within 5% of the rail’s official designation, regardless of load. It doesn’t actually mention that the PSU shouldn’t explode, though I expect they figured it was implied. Exploding is a failure in my book regardless.

It is also worth knowing that I will be testing this PSU at both outdoor ambient temperatures (typically between 10 °C and 20 °C here this time of year) as well as in the Enclosure of Unreasonable Warmth. TEUW is a precision engineered enclosure that I use to route the exhaust air from the PSU right back into the intake fan, it is adjustable to hold the intake air temperature at (almost) any level I want it. This way I can test the PSU’s response to hot conditions as well as cold conditions. For the hot testing I will be running the intake temp as close to the unit’s maximum rated temperature as possible. TEUW, in case you’re curious, is a cardboard box. Sometimes a Styrofoam medical supply shipment cooler, if the unit is too efficient for the cardboard box.

That’s 0.16% regulation there on the 12 V rail. Not 1.6% mind you, 0.16%. Epic. 5 V is a bit looser at 1.38%, but still very very good. 3.3 V is the loosest at 1.8%, which is still very good. Combined we get 1.1% regulation, just the tiniest hair over the generally accepted Excellent mark of 1.0%. Still, given the 12 V rail’s results, I’m going to call it Excellent anyway. The fan is extremely quiet at low and medium loads (at 9 °C, anyway), I couldn’t hear anything unless my ear was within 2″ of the fan. Starting at 912 W load it sped up a little bit, enough that I could hear it at 5″, just barely. At full load it sped up a good bit more, but was still on the quiet end of things and devoid of annoying mechanical/motor noises. Once it went into TEUW the fan kicked into high gear, at sustained full load and an intake air temperature of around 16 °C it starts ramping up until at 40 °C intake temperatures it’s moving a considerable amount of air, and making a fair bit of noise. One the plus side, it’s almost entirely air noise and hence not an annoying noise. You’re unlikely to hear it over a HW combination that draws 1200 W.

I was interested to see the 5 V and 3.3 V rails increase in voltage as the load went up, that’s pretty rare.

Bottom line for regulation testing:  Excellent.

Load Testing Part Two: Ripple

Ripple is fluctuation of the PSU’s output voltage caused by a variety of factors. It is pretty much impossible to have zero ripple in a SMPS computer power supply because of how a SMPS works, so the question is how much ripple is there? In the regulation testing phase we found out how the PSU does at keeping the average voltage at a set level, now we’re going to see what that voltage is doing on really short time frames. The ATX spec says that the 12 V rail cannot have more than 120 mV peak to peak ripple, the 5 V and 3.3 V rails need to stay under 50 mV.

If that isn’t complicated enough for you, there are three forms of ripple to keep track of as well. Long-term ripple from the PSU’s controller adjusting the output voltage and over/undershooting, correcting, overshooting, etc. Medium-term ripple from the voltage controller charging and discharging the inductor(s) and capacitor(s) that make up the VRM, and very short-term ripple caused by the switching itself. The first and second forms are the most important, if they are out of spec it can cause instability at best or damage in extreme situations. The very short-term (I call it transient ripple) flavor is less crucial, excessive amounts can still cause issues though it takes more of it to do so. The ATX spec does not differentiate, as far as the spec goes 121 mV of transient ripple is just as much of a failure as 121 mV of medium or long term ripple.

I test ripple in a few difference ways, first I test it during the cold load testing. It is tested at zero load and maximum load first. During the hot load testing I test the ripple at maximum load again. I have recently started testing ripple at fairly random loads with the unit still hot, it’s a bit unorthodox (a bit? maybe a lot) but has found issues in the past that did not show up with other test methods.

We’re starting with zero load as usual.

Words cannot properly express how impressed I am without brutally violating the PG-13 rating of Overclockers.com. Suffice to say that this is the first unit ever to get all three rails into single digit ripple at any time on my scope.

Next up, full load! Scope’s at 2ms / 10mV now.

At full load the numbers go up a bit, but they’re all still in the Excellent category. I have no complaints at all! Interestingly these are the first (ever) DC-DC secondaries that almost completely lack transients even on my analog scope. There are switching spikes, but we’re talking 2 mV to 4 mV. Be Quiet! did an amazing job here. The only unit that has given me better results was the HALE90 V2, and it uses AC-DC secondary bits and hence doesn’t count. Very very impressive.

Let’s see if it can handle the heat, scope remains at 2ms / 10mV.

It doesn’t just handle it, it ignores it completely. 12 V likes the heat, even.

Final ripple testing rating: Excellent.

Dissection

Disclaimer: Power supplies can have dangerous voltages inside them even after being unplugged, DO NOT OPEN POWER SUPPLIES. It’s just not a good idea. Opening a power supply and poking around inside could very well kill you. Don’t try this at home. Don’t try this at work. Just don’t do it.

First up, the fan:

Interesting blades, whether they work or not is hard to say, but the thing does move a lot of air for the noise it makes.

With our overview we see a Seasonic X platform, that explains a lot. To be specific this is the same platform as the X1250. Different parts though.

We’ll start our tour at the transient filter as usual.

The receptacle contains two inductors (or one common mode inductor, not sure), two Y caps and one X cap. The PCB has an additional four Y caps, an X cap, two inductors, a TVS Diode for surge protection, a fuse, a thermistor for inrush current protection and a relay to shut the thermistor off once the unit has started. It’s a very complete filter.

The rectifiers are GBJ250(something) parts, the last digit is the voltage and I cannot read it at all. The GBJ25 part is enough to ID the rectifiers as 25 amp units though, so in theory between the two of them they can rectify more current than an average clothes dryer uses. That’s my kind of excess right there. The APFC switches are a pair of 6R125P units as you can see, they’re rated at 25 amps at 25 °C and 16 amps at 100 °C and 650 V either way. The diode is a C3D10060 unit, rated at 10 amps and 600 volts. The four primary switches are 6R190C6 MOSFETs rated at 20 to 13 amps at 25 to 100 °C, and 600 volts.

On the secondary side of things we have eight 2R640 (40 V, 100 A, 175 °C) MOSFETs on the bottom of the PCB, they have heatsinks coming out the top of the PCB and a large thermal pad attached to the bottom of the case. Note their 175 °C rating! That’s huge.

The modular connector board has the 5 V, 3.3 V, and Fan DC-DC units, the 5 V and 3.3 V rails each get three KO332 MOSFETs, I can’t find their ratings. The controller is widely used and works great, as we saw earlier.

As you can see the PCIe power connectors are on the main PCB, not the modular board. The auxiliary fan control linear regulator I cannot find any data on, be quiet! says 0.8 A or less combined load though, so I’d stick to that. The PSU fan has its own controller on the main PCB.

Flipping the main PCB over we can check out the soldering:

Perfect. The only non-perfect things are so incredibly nitpicky that I’d feel silly listing them. The worst soldering I can find is better soldering than most PSUs have. The soldering is that good.

Now for the disclaimer: This is the second unit I’ve inspected. The first had a couple issues. In response to this be quiet! sent a second, sealed, never opened since the factory (it’s obvious with these units) unit. That is what you see above. Then they sent people to the factory that produces these units to find out what was going on and how the (minor, but potentially issue causing) issues slipped through. I’m quite impressed with their response. Between that and the fact that everybody gets two tries, the first unit will not be held against be quiet!
Also, worth noting is that all the test results are from the first unit.

Final Words and Conclusion

From the very beginning of this review I’ve been highly impressed with this PSU. It’s a design that clearly had some thought put into it on many levels, and the results really show it.

The cable selection is excellent, you get a huge variety of well thought out cable options.

The regulation is excellent as well, very impressive.

Ripple control is better than any DC-DC unit I’ve looked at so far, very impressive!

The looks of the unit are quite nice as well, it blends snazzy looks with functional noise dampening and results in a very nice looking, quiet, PSU.

The fan is extremely quiet at low and medium loads, when hot at full load there’s a fair bit of airflow noise but no mechanical or motor noise.

The parts selection and build quality are excellent, as is the soldering. be quiet!! and Seasonic did an excellent job there.

The current price for this unit is roughly $300 ($319.99 at NCIX), that’s significantly more expensive than similarly rated and performing units (like the Seasonic X 1250 W unit it is based on, at ~$250). This is the price you pay for the amazing cable selection and such, plus it’s a brand new unit with no price cuts so far. How good the value is depends on what you’re looking for, personally I don’t think you would be disappointed in what you got for the extra money.

The accessories pack is amazing, screws, thumbscrews, zip ties, velcro wraps, and lots of everything.

I’ll make some bullet points. There are pros:

• Excellent regulation.
• Excellent ripple control.
• Extremely quiet at low to medium loads.
• Looks great.
• Huge variety of cables included.
• Best accessories pack I’ve seen in a while, maybe ever.

There are some cons too:

• Not cheap.
• There really aren’t any more cons.

All told I’m very impressed with the be quiet! Dark Power Pro 10 1200 W Power Supply and approve it for consideration as your next PSU.

Click the approved stamp for info on exactly what it means.

 — Bobnova