be quiet! Dark Power 13 850W Report (Page 3 of 4)

Page 3 - Physical Look - Inside

As always, we opened up our be quiet! Dark Power 13 850W power supply to take a detailed look at what is going on inside. Please note that doing this at home may void your 10-year warranty even though you can do so without breaking any seals to leave behind clear evidence. Either way, for the benefit of you, we cracked ours open so you do not need to, haha. There are no user serviceable parts inside.

Disassembling the be quiet! Dark Power 13 850W was both straightforward and a bit challenging with the removal of four screws. Two of the screws are located behind the specifications label on one side, so it required some effort to do so without damaging it for reassembly later on. All of the screws are also hex screws, which many people do not have a screwdriver for. Of course, we have all the tools here at APH Networks, but they were all tightened it to some unholy torque setting from the factory and I ended up stripping one of them by accident.

Our photo above shows an overhead view of its internal components. Its OEM is FSP, a reputable PSU manufacturer that also sells products under their own brand. The Dark Power 13 850W is built on the same platform as the 750W and 1000W models. It features an LLC full bridge topology with DC-to-DC converters. At first glance, the build quality appears to be excellent. There are three main heatsinks inside. Two of them are painted black and one of them is silver, located on the primary side. Additionally, there are two smaller sized heatsinks in its original aluminum finish that resides on the secondary side.

Pulling the enclosure apart, I had to remove the fan frame halves and impeller separately to get to the internal inspection. The fan frame is separated into two parts that are attached to the side of the PSU, while the impeller is screwed into three poles underneath it. This split fan inlet design increases airflow while reducing turbulence for lower noise according to the company.

The transient filter stage is the first input stage of a computer power supply, so we will take a look at that first. be quiet!, regardless of the OEM, has done a great job in the past to make sure their power supplies met or exceeded the recommended requirements in the past, and the Dark Power 13 850W is no exception. The be quiet! Dark Power 13 850W has one metal oxide varistor, three metalized polyester X-capacitors, four ceramic Y-capacitors, two ferrite coils, and two gas discharge tubes. This is three times the amount of X and two times the amount of Y capacitors than recommended.

The active PFC circuit featured on the be quiet! Dark Power 13 850W is a bridgeless design. A bridgeless design is great for power efficiency, but more exotic designs nowadays feature bridgeless totem-pole PFC thanks to new semiconductor materials for power switches. Four STMicroelectronics STB57N65M5 rectifier MOSFETs are used, located on the large silver heatsink. The standby circuit still features a PFC Device Corporation P15L50N5 Schottky rectifier though.

Further down the line, on the outside of the largest heatsink, we can two Infineon IPA60R120P7 power transistors. Each is certified for up to 16A at 100c. These transistors present a maximum resistance of 120 mΩ and typical resistance of 100 mΩ when turned on according to the manufacturer's data sheet. This on characteristic is called Static Drain-Source On-Resistance, or commonly abbreviated as RDS(on). The more efficient the component is, the lower the RDS(on) value, since it wastes less power with lower resistance. Two Cree C3D06060A boost diodes are adjacent, with one on the same side of the heatsink and one on the opposite. Four Alpha & Omega AOTF190A60L MOFSETs, located on the smaller heatsink next to the bulk capacitors, are used as the main switchers on the Dark Power 13 850W power supply. Each is certified for up to 12A at 100c, maximum resistance of 190 mΩ, and typical resistance of 170 mΩ.

On the primary side, we can see two Japanese brand Nippon Chemi-Con capacitors. 100% Japanese brand capacitors are specified on the marketing material, so this is to be expected. Our 850W version of be quiet!'s Dark Power 13 series power supply incorporates two capacitors, one 470µF x 420V and one 330µF x 420V, in parallel for a total of 800µF capacitance. They are rated at 105c, whereas more value-oriented power supplies usually use 85c rated capacitors.

Other components that can be spotted on the primary side include an Infineon ICE2PCS02 on the add-in board next to the APFC components. A Champion CM6901T2X SLS, SRC/LLC + SR resonant controller is located on the add-in board between the main switchers and the rear connector board. Two Novosense NSi6602 dual channel gate driver ICs are located at the bottom of the main PCB.

On the secondary side, we can see more Nippon Chemi-Con and Rubycon capacitors rated at 105c. All rectifiers produce the +12V out, while the +5V and +3.3V outputs are generated from the +12V output using a DC-to-DC converter within as with modern high efficiency power supplies. Six Toshiba TPHR8504PL power MOSFETs are responsible for generating the +12V output, located at the bottom of the main PCB. The TPHR8504PL's rated continuous drain current is 150A at 25c. It has an RDS(on) value of 1.4 mΩ maximum and 1.0 mΩ typical at 25c.

Six Infineon BSC0901NS MOSFETs are responsible for generating the +5V and +3.3V outputs, located on the vertical board perpendicular to the rear connector board. The BSC0901NS's rated continuous drain current is 94A at 100c. It has an RDS(on) value of 1.9 mΩ maximum and 1.6 mΩ typical. An uPI Semiconductor uP3861P dual channel synchronous rectified buck controller and Weltrend WT7527RA monitoring IC for over/under current and over/under voltage protection can be seen on the same board as well. The datasheets for all components mentioned in this review can be found on their respective manufacturer's websites.

At the back, we have a large daughterboard covering the entire rear panel for the modular cable sockets. All connection points are soldered directly to the add-on PCB after the secondary stage to reduce power transmission loss compared to having wires. The output connector configuration can be seen on the previous page. Overall, the internal build quality of be quiet!'s Dark Power 13 850W is very good. Components are arranged very well for optimal cooling with practically no wires running around inside, and solder points on its black PCB is quite clean in general. I would say the be quiet! Dark Power 13 850W is generally very good with regards to the selection of components used under the hood, appropriate for its performance class.

Lastly, we see a 135mm fan that provides cooling to the be quiet! Dark Power 13 850W's internal components. It is connected to the mainboard using a 2-pin connector. A 135mm fan is only marginally smaller than the 140mm maximum you can fit in an ATX power supply, and it is beneficial in most cases in providing lots of airflow at lower speeds for quiet operation.

The fan is a be quiet! Silent Wings BQ SIW3-13525-HF, as shown in our photo above. The Silent Wings BQ SIW3-13525-HF is a fluid dynamic bearing fan with a 6-pole fan motor specified at 0.56A for a maximum of speed of 1800 RPM. There is no semi-fanless mode, but the fan speed will vary with load and be quiet! uses a very quiet profile. Fans with fluid dynamic bearings generally have much longer lifespans compared to sleeve bearing fans, and is quite suitable for this application.

Page Index
1. Introduction, Packaging, Specifications
2. Physical Look - Outside
3. Physical Look - Inside
4. Minor Tests and Conclusion