[nextpage title=”Introduction”]
The German brand be quiet! is releasing today a new high-end power supply series, the Dark Power Pro 10, with models ranging from 550 W to 1,200 W. The 850 W model has the coveted 80 Plus Platinum certification, while all other models have the 80 Plus Gold certification. Let’s test the 650 W version and see if it is a good pick.
The 550 W, 650 W, and 750 W models are manufactured by FSP, while the 850 W, 1,000 W, and 1,200 W are manufactured by Seasonic.
Figure 1: be quiet! Dark Power Pro 10 650 W power supply
Figure 2: be quiet! Dark Power Pro 10 650 W power supply
The be quiet! Dark Power Pro 10 650 W is 7.1” (180 mm) deep, using a 135 mm fluid-dynamic bearing fan on its bottom (be quiet! BQT T13525-HF18, a.k.a. “Silent Wings 2”).
The reviewed power supply has a modular cabling system with 15 connectors: four for video card power cables, five for peripheral/SATA cables, one for the ATX12V/EPS12V cable, four for fan power cables, and one for the “overclocking” panel, which is used for selecting whether the power supply will use a multiple +12 V rail or a single +12 V rail configuration. Only the main motherboard cable is permanently connected to the power supply. This power supply comes with the following cables:
- Main motherboard cable with a 20/24-pin connector, 24” (61 cm) long
- One connector with two cables, one with two ATX12V connectors that together form an EPS12V connector, and one with an EPS12V connector, 27.6” (70 cm) long
- One cable with two ATX12V connectors that together form an EPS12V connector, 27.6” (70 cm) long
- Two connectors, each with two cables with one six-pin connector for video cards, 23.6” (60 cm) long
- One cable with one six-pin connector for video cards, 23.6” (60 cm) long
- Two cables, each with three SATA power connectors, 23.6” (60 cm) to the first connector, 5.9” (15 cm) between connectors
- One cable with one SATA power connector, 23.6” (60 cm) long
- One cable with two SATA power connectors, two standard peripheral power connectors, one floppy disk drive power connector, 23.6” (60 cm) to the first connector, 5.9” (15 cm) between connectors
- One cable with three standard peripheral power connectors, 23.6” (60 cm) to the first connector, 5.9” (15 cm) between connectors
- Two cables, each with one standard peripheral power connector, 23.6” (60 cm) long
- Four cables, each with one standard peripheral power connector and one standard three-pin fan power connector, 17.7” (45 cm) to the first connector, 5.9” (15 cm) between connectors
All wires are 18 AWG, which is the minimum recommended gauge. The number of connectors available is completely overkill for a 650 W product. It allows you to install, out of the box, two high-end video cards that require two auxiliary power connectors each. If you buy additional cables, you can use this power supply with up to four video cards. This is the first time we’ve seen a 650 W unit with such a configuration. Another highlight of the cable configuration is the presence of cables with lots of connectors as well as cables with a single connector. This way, you can install only the cables you are going to actually use, preventing your computer from ending up with a lot of unused cables hanging inside. For example, if you have only one hard drive, you can install the cable that has only one SATA power connector. On competing products, you would have to use a cable where two or three connectors would be left unused, occupying space inside the case.
Another highlight of the Dark Power Pro 10 650 W is the presence of four cables for powering fans. This way, you can have at least some of the fans available on your case controlled by the temperature sensor available inside the power supply.
The reviewed power supply comes with a switch for you to select your favorite configuration for the +12 V output: single-rail (with the switch turned on) or multiple-rail (the default configuration). The unit also comes with a jumper in case you want to “permanently” configure the unit as single-rail but don’t want to install the switch.
Figure 3: Cables
Figure 4: Single-rail/multiple-rail switch
Let’s now take an in-depth look inside this power supply.
[nextpage title=”A Look Inside the be quiet! Dark Power Pro 10 650 W”]
We decided to disassemble this power supply to see what it looks like inside, how it is designed, and what components are used. Please read our “Anatomy of Switching Power Supplies” tutorial to understand how a power supply works and to compare this power supply to others.
On this page we will have an overall look, and then in the following pages we will discuss in detail the quality and ratings of the components used.
Figure 5: Top view
Figure 6: Front quarter view
Figure 7: Rear quarter view
Figure 8: The printed circuit board
[nextpage title=”Transient Filtering Stage”]
A
s we have mentioned in other articles and reviews, the first place we look when opening a power supply for a hint about its quality, is its filtering stage. The recommended components for this stage are two ferrite coils, two ceramic capacitors (Y capacitors, usually blue), one metalized polyester capacitor (X capacitor), and one MOV (Metal-Oxide Varistor). Very low-end power supplies use fewer components, usually removing the MOV and the first coil.
In the transient filtering stage, this power supply is flawless, with one X capacitor and two Y capacitors more than the minimum required, and with an integrated circuit called CAPZero to reduce power loss.
Figure 9: Transient filtering stage (part 1)
Figure 10: Transient filtering stage (part 2)
On the next page, we will have a more detailed discussion about the components used in the be quiet! Dark Power Pro 10 650 W.
[nextpage title=”Primary Analysis”]
On this page we will take an in-depth look at the primary stage of the be quiet! Dark Power Pro 10 650 W. For a better understanding, please read our “Anatomy of Switching Power Supplies” tutorial.
This power supply uses one GBJ25L06 rectifying bridge, which is attached to an individual heatsink. This bridge supports up to 25 A at 115° C. So, in theory, you would be able to pull up to 2,875 W from a 115 V power grid. Assuming 80% efficiency, the bridge would allow this unit to deliver up to 2,300 W without burning itself out (or 2,587.5 W if 90% efficiency). Of course, we are only talking about this particular component. The real limit will depend on all the components combined in this power supply.
Figure 11: Rectifying bridge
The active PFC circuit uses three STF26NM60N MOSFETs, each supporting up to 20 A at 25° C or 12.6 A at 100° C in continuous mode (see the difference temperature makes) or 80 A at 25° C in pulse mode. These transistors present a maximum 165 mΩ resistance when turned on, a characteristic called RDS(on). The lower the number the better, meaning that the transistor will waste less power, and the power supply will have a higher efficiency.
Figure 12: Active PFC diode and transistors
The active PFC circuit is controlled by an ICE2PCS02 integrated circuit.
Figure 13: Active PFC controller
The output of the active PFC circuit is filtered by two 270 µF x 450 V Japanese electrolytic capacitors, from Matsushita (Panasonic), labeled at 105° C and connected in parallel. This is the equivalent of a single 540 µF x 450 V capacitor.
In the switching section, another two STF26NM60N MOSFETs are employed using a resonant configuration. The specifications for these transistors were already discussed above.
Figure 14: The two switching transistors
The switching transistors are controlled by a CM6901 integrated circuit.
Figure 15: Resonant controller
Another interesting feature present in the primary of this power supply that is worth mentioning is the presence of a SENZero chip (SEN013DG), which reduces the amount of energy the power supply consumes when in standby mode.
Figure 16: The SENZero chip
Let’s now take a look at the secondary of this power supply.
[nextpage title=”Secondary Analysis”]
The be quiet! Dark Power Pro 10 650 W uses a DC-DC design in its secondary. This means that the power supply is basically a +12 V unit, with the +5 V and +3.3 V outputs produced by two smaller power supplies connected to the main +12 V rail. Also, the +12 V output uses a synchronous design, where the rectifiers were replaced with MOSFETs. Both designs are used to increase efficiency.
The maximum theoretical current that each line can deliver is given by the formula I / (1 – D) where D is the duty cycle used and I is the maximum current supported by the rectifying diode. As an exercise, we can assume a duty cycle of 30 percent.
The +12 V output uses four IRFB3206GPbF MOSFETs, each supporting up to 120 A at 25° C in continuous mode or 840 A at 25° C in pulse mode, with a maximum RDS(on) of 3 mΩ.
Figure 17: The +12 V MOSFETs
As explained, the +5 V and +3.3 V outputs are produced by two DC-DC converters
. Both are located on the same daughterboard that is soldered to the main printed circuit board. The two converters are controlled by a single integrated circuit, an APW7158. Each converter uses four IRLR8729pbF MOSFETs, each one supporting up to 58 A at 25° C or 41 A at 100° C in continuous mode or up to 260 A at 25° C in pulse mode, with a maximum RDS(on) of 8.9 mΩ.
Figure 18: The DC-DC converters
Figure 19: The DC-DC converters
This power supply uses a PS232F monitoring integrated circuit, which supports over voltage (OVP), under voltage (UVP), and over current (OCP) protections. There are four +12 V over current protection (OCP) channels, matching the number of +12 V rails advertised by the manufacturer.
Figure 20: Monitoring circuit
The electrolytic capacitors that filter the outputs are also Japanese, from Chemi-Con and Rubycon, and labeled at 105° C, as usual. This unit also makes use of solid capacitors.
[nextpage title=”Power Distribution”]
In Figure 21, you can see the power supply label containing all the power specs.
Figure 21: Power supply label
This power supply is advertised as having four +12 V rails, which is correct, since the monitoring integrated circuit has four +12 V over current protection (OCP) channels, and we clearly saw four current sensors (“shunts”) on the component side of the printed circuit board. See Figure 22. (Actually, there are six shunts, but RS243 is connected in parallel to RS244, and RS245 is connected in parallel to RS246, so the six shunts act as four.) Click here to understand more about this subject.
Figure 22: Shunts
The four +12 V rails are distributed as follows:
- +12V1 (RS240): The main motherboard cable and the peripheral and SATA connectors
- +12V2 (RS241): The ATX12V/EPS12V connector
- +12V3 (RS243/RS244): The first and second video card power connectors
- +12V4 (RS245/RS246): The third and fourth video card power connectors
This distribution is perfect. However, when using two connectors for video cards on the power supply (i.e., when you install two video cards that require two auxiliary power connectors each, since each connector has two cables), don’t install them side-by-side, or they will be connected to the same rail; skip one connector (i.e., use the first and the third connectors) to make each video card use a separate rail. Of course, if you configure the power supply to use a single-rail configuration, what we are saying won’t matter.
How much power can this unit really deliver? Let’s find out.
[nextpage title=”Load Tests”]
We conducted several tests with this power supply, as described in the article, “Hardware Secrets Power Supply Test Methodology.”
First we tested this power supply with five different load patterns, trying to pull around 20%, 40%, 60%, 80%, and 100% of its labeled maximum capacity (actual percentage used listed under “% Max Load”), watching the behavior of the reviewed unit under each load. In the table below, we list the load patterns we used and the results for each load.
If you add all the powers listed for each test, you may find a different value than what is posted under “Total” below. Since each output can have a slight variation (e.g., the +5 V output working at +5.10 V), the actual total amount of power being delivered is slightly different than the calculated value. In the “Total” row, we are using the real amount of power being delivered, as measured by our load tester.
The +12VA and +12VB inputs listed below are the two +12 V independent inputs from our load tester. During this test, we configured the power supply to use a single +12 V rail design, so both inputs were connected to the power supply’s single +12 V rail. (We connected the EPS12V connector to the +12VB input.)
| Input | Test 1 | Test 2 | Test 3 | Test 4 | Test 5 |
| +12VA | 5 A (60 W) | 10 A (120 W) | 14.5 A (174 W) | 19 A (228 W) | 23.5 A (282 W) |
| +12VB | 5 A (60 W) | 10 A (120 W) | 14 A (168 W) | 19 A (228 W) | 23.5 A (282 W) |
| +5 V | 1 A (5 W) | 2 A (10 W) | 4 A (20 W) | 6 A (30 W) | 8 A (40 W) |
| +3.3 V | 1 A (3.3 W) | 2 A (6.6 W) | 4 A (13.2 W) | 6 A (19.8 W) | 8 A (26.4 W) |
| +5VSB | 1 A (5 W) | 1.5 A (7.5 W) | 2 A (10 W) | 2.5 A (12.5 W) | 3 A (15 W) |
| -12 V | 0.5 A (6 W) | 0.5 A (6 W) | 0.5 A (6 W) | 0.5 A (6 W) | 0.5 A (6 W) |
| Total | 139.2 W | 269.8 W | 389.4 W | 520.3 W | 646.6 W |
| % Max Load | 21.4% | 41.5% | 59.9% | 80.0% | 99.5% |
| Room Temp. | 46.3° C | 44.8° C | 45.0° C | 47.2° C | 45.7° C |
| PSU Temp. | 52.4° C | 52.2° C | 52.4° C | 54.3° C | 52.2° C |
| Voltage Regulation | Pass | Pass | Pass | Failed at +5VSB | Failed at +5VSB |
| Ripple and Noise | Pass | Pass | Pass | Pass | Pass |
| AC Power | 156.6 W | 298.9 W | 433.0 W | 585.8 W | 738.0 W |
| Efficiency | 88.9% | 90.3% | 89.9% | 88.8% | 87.6% |
| AC Voltage | 117.2 V | 115.7 V | 114.9 V | 113.2 V | 111.3 V |
| Power Factor | 0.995 | 0.927 | 0.998 | 0.998 | 0.998 |
| Final Result | Pass | Pass | Pass | Pass | Pass |
In our tests, the be quiet! Dark Power P
ro 10 650 W presented efficiency between 87.6% and 90.3%, perfectly matching the 80 Plus Gold certification, which promises a minimum efficiency of 87% at light (i.e., 20%) and full loads, and 90% at typical (i.e., 50%) load.
The ATX12V specification states that positive voltages must be within 5% of their nominal values, and negative voltages must be within 10% of their nominal values. We always expect power supplies to present voltages within 3% of their nominal values to consider them as “flawless.” You can see the results in the table below. We marked in red the values that were outside their proper range.
| Input | Test 1 | Test 2 | Test 3 | Test 4 | Test 5 |
| +12VA | ≤ 3% | ≤ 3% | ≤ 3% | ≤ 3% | ≤ 3% |
| +12VB | ≤ 3% | ≤ 3% | ≤ 3% | ≤ 3% | ≤ 3% |
| +5 V | ≤ 3% | ≤ 3% | ≤ 3% | ≤ 3% | ≤ 3% |
| +3.3 V | ≤ 3% | ≤ 3% | ≤ 3% | ≤ 3% | +3.18 V |
| +5VSB | ≤ 3% | ≤ 3% | ≤ 3% | +4.73 V | +4.74 V |
| -12 V | -11.48 V | -11.63 V | ≤ 3% | ≤ 3% | ≤ 3% |
Let’s discuss the ripple and noise levels on the next page.
[nextpage title=”Ripple and Noise Tests”]
Voltages at the power supply outputs must be as “clean” as possible, with no noise or oscillation (also known as “ripple”). The maximum ripple and noise levels allowed are 120 mV for +12 V and -12 V outputs, and 50 mV for +5 V, +3.3 V and +5VSB outputs. All values are peak-to-peak figures. We consider a power supply as being top-notch if it can produce half or less of the maximum allowed ripple and noise levels.
The be quiet! Dark Power Pro 10 650 W provided very low ripple and noise levels, as you can see below.
| Input | Test 1 | Test 2 | Test 3 | Test 4 | Test 5 |
| +12VA | 31.2 mV | 32.2 mV | 36.0 mV | 37.6 mV | 42.8 mV |
| +12VB | 32.2 mV | 33.4 mV | 38.6 mV | 42.6 mV | 46.2 mV |
| +5 V | 5.2 mV | 5.6 mV | 6.4 mV | 8.6 mV | 10.6 mV |
| +3.3 V | 6.2 mV | 8.8 mV | 9.8 mV | 12.6 mV | 14.6 mV |
| +5VSB | 10.6 mV | 16.0 mV | 18.6 mV | 23.6 mV | 26.6 mV |
| -12 V | 30.4 mV | 39.2 mV | 45.6 mV | 52.4 mV | 59.6 mV |
Below you can see the waveforms of the outputs during test five.
Figure 23: +12VA input from load tester during test five at 646.6 W (42.8 mV)
Figure 24: +12VB input from load tester during test five at 646.6 W (46.2 mV)
Figure 25: +5V rail during test five at 646.6 W (10.6 mV)
Figure 26: +3.3 V rail during test five at 646.6 W (14.6 mV)
[nextpage title=”Overload Tests”]
Below you can see the maximum we could pull from this power supply. The objective of this test is to see if the power supply has its protection circuits working properly. This unit passed this test, since it shut down when we tried to pull more than what is listed below. During this test, noise and ripple levels were still low and all voltages were within 3% of their nominal values, which is curious, since the +5VSB and +3.3 V outputs had exited this narrow range during our full-load test.
| Input | Overload Test |
| +12VA | 25.5 A (306 W) |
| +12VB | 25.5 A (306 W) |
| +5 V | 8 A (40 W) |
| +3.3 V | 8 A (26.4 W) |
| +5VSB | 3 A (15 W) |
| -12 V | 0.5 A (6 W) |
| Total | 692.8 W |
| % Max Load | 106.6% |
| Room Temp. | 47.0° C |
| PSU Temp. | 53.8° C |
| AC Power | 798.0 W |
| Efficiency | 86.8% |
| AC Voltage | 110.7 V |
| Power Factor | 0.999 |
[nextpage title=”Main Specifications”]
The main specifications for the be quiet! Dark Power Pro 10 650 W power supply include:
- Standards: ATX12V 2.31 and EPS12V 2.92
- Nominal labeled power: 650 W
- Measured maximum power: 692.8 W at 47° C
- Labeled efficiency: Up to 94%, 80% Plus Gold certification, 87% minimum at light (i.e., 20%) and full loads, and 90% minimum at typical (i.e., 50%) load
- Measured efficiency: Between 87.6% and 90.3%, at 115 V (nominal, see complete results for actual voltage)
- Active PFC: Yes
- Modular Cabling System: Yes
- Motherboard Power Connectors: One 20/24-pin connector, one connector with two ATX12V connectors that together form an EPS12V connector, and one connector with two cables, one with two ATX12V connectors that together form an EPS12V connector and one with one EPS12V connector
- Video Card Power Connectors: Five six/eight-pin connectors on separate cables
- SATA Power Connectors: Nine on four cables
- Peripheral Power Connectors: Seven on four cables
- Floppy Disk Drive Power Connectors: One
- Protections (as listed by the manufacturer): Over voltage (OVP), under voltage (UVP), over current (OCP), over power (OPP), and short-circuit (SCP)
- Are the above protections really available? Yes.
- Warranty: Five years
- More Information: https://www.bequiet.com
- MSRP in the U.S.: USD 150.00
[nextpage title=”Conclusions”]
It is very clear that be quiet! is trying, with the Dark Power Pro 10, to create the most flawless and complete PC power supply series available on the market today. The cable configuration of the 650 W version is simply overkill. The single/multiple rail switch puts an end to the endless discussion of which configuration is better: you simply choose which one you think it is better. We really loved that this power supply comes with four cables for fans with two power connectors each; this way you can make all the fans available on your case to be temperature-controlled by the pow
er supply.
Performance-wise, the Dark Power Pro 10 650 W presented high efficiency between 87.6% and 90.3% and low noise and ripple levels. Voltage regulation could be better, as the +5VSB output dropped below the minimum allowed during two of our five tests.
Technically, it is a good power supply. The only real negative is its price. The 650 W model will reach the market with a suggested price of USD 150, which is very high for a 650 W model. But if you are a user who only demands the best in class, this may be the power supply you are looking for.