be quiet! Dark Power Pro 11 850W PSU Review

Allan 'Zardon' Campbell May 12, 2015 Featured Tech Reviews, Power Supplies

be quiet! are using one of their own 135mm SilentWings 3 fans, with a funnel shaped vent. The funnel shape is said to improve airflow while reducing turbulence. The new 6 pole motor and redesigned bearing lower noise further. This fan, as mentioned already in the review has the slowest start up speed of any fan on the market – 250 rpm.

This looks to be an FSP design – the topology is ‘Full Bridge + LLC + SR + DC/DC'. The Full Bridge implementation relates to the number of MOSFETs used in the PWM stage. The MOSFETS are responsible for creating high frequency alternating current – the best efficiency for the main transformation.

A Half Bridge design uses two MOSFETS, a Full Bridge doubles this to four – reducing the load across them all. The LLC part of the name relates to the use of two inductors and one capacitor – this smooths out the alternating current – giving very high levels of efficiency, critical to achieve 80 Plus Platinum efficiency.

This unit is engineered to very high standards, as we would expect from a high end be quiet! release. Soldering quality is good throughout.

There are no less than 8 daughtercards incorporated into the Dark Power Pro 11 850W unit (see above).

1. CM board (Cable management).
2. DC/DC board for 3.3 and 5V.
3. 5VSB board.
4. LLC board with the C of LLC.
5. Protection board.
6. Fan control board.
7. LLC control board (with IC).
8. -12V board.

3.3V and 5V rails are generated from the 12V DC after the main transformation. This unit is also equipped with two parallel placed main transformers (one for Standby 5V circuit) – to reduce heat emission and to give higher efficiency levels.

This design has two high grade 105c rated Japanese capacitors in the primary stage – rated 420v 470uF. It is always reassuring to see Nippon Chemi Con utilised. be quiet! say they have enhanced the design of the PFC stage by using special high quality plastic capacitors to reduce noise – exceeding the quality of the capacitor in the previous generation model.