As if the cable summary wasn't long enough with the 550W model, the 850W model adds an extra set of PCI-E connectors as well as a 4-pin aux power connector for the motherboard. Seven PCI-E, nine SATA, seven Molex and one FDD connector make sure you've got plenty of ways to power your devices over varying length cables. There are also four fan cables so that the power supply can control fan speed on its own.
Just as with the 550W model, rail distribution is a bit complicated with the Dark Power Pro 10 850W unit. It has four 12V rails. Two are rated for 30A and two are rated for 45A. Nowhere in the documentation we received on the unit were we able to find which connections are attached to which rails. For our testing purposes, we will be using what be quiet! calls the "high performance single rail mode" by utilizing the included overclocking key.
A Look Inside
Once opened up, you can see where the similarities between the 550W and 850W models end. There is a significant design difference between the two and our conversations with be quiet! reveal they have done a lot of work with Seasonic to redesign the unit. There is a spot on the PCB for a third capacitor on the primary side of the power supply. It is fairly safe to say that spot isn't blank on the 1000W and 1200W models.
A pair of Nippon Chemi-Con caps cover the primary side of the be quiet! Dark Power Pro 850W power supply.
More Japanese made Nippon Chemi-Con capacitors can be found on the secondary side of the PSU.
be quiet! chose a slightly different fan for the Dark Power Pro 10 850W power supply. It is the BQT T13525-XF20. The only difference is that the fan is a 2000 RPM fan instead of a 1500 RPM fan. It will be a bit louder at 24.2 dbA under full load but that is still very quiet for a power supply.