A Detailed Look
The BitFenix Whisper M 850W power supply enclosure is painted matte black and measures 160mm (6.3”) long. The back panel includes an AC receptacle and main power On-Off switch.
The 850 watt power supply incorporates BitFenix’s Intelligent Fan Control, which is designed to provide quiet operation from low through mid power (up to 70% load).
The power supply uses a 135mm, eleven blade fan for cooling. The Martech fan (DF1352512SEHN) is rated for 0.60A at 12 VDC and uses Fluid Dynamic Bearing (FDB) for quiet operation. We have never seen this particular brand of fan used in a power supply before and don't know much about its history or reliability.
The front panel on the Whisper M 850W PSU incorporates eleven modular cable connectors. Note the four VGA and single CPU connectors are nicely labelled. However, this power supply (and the 750W version) comes with four PCI-E cables and two CPU cables. Unfortunately you can’t use them all at the same time as there are not enough connectors. If you need both CPU cables you can plug the second cable into one of the PCI-E connectors (the VGA and CPU connectors have the same pin out). This configuration will most likely work for the majority of users but it would have been better to see two CPU connectors at this power level.
All of the modular cables are flat, ribbon-style.
Under the Hood
Here are a few pictures showing the layout and components inside the BitFenix Whisper M 850W power supply. BitFenix is using Channel Well Technology (CWT) as their partner and OEM for the Whisper M series.
The power supply uses an LLC resonant topology to lower power losses and boost efficiency during switching. The power supply uses DC-to-DC converters for increased efficiency to generate the +3.3V and +5V outputs from the +12V supply.
The layout of components is clean while the soldering appears to be good. All of the capacitors used inside the PSU are Japanese made. The single primary bulk capacitor is made by Nichicon and rated for 680uF, 400V and 105°C.