Strangely for Corsair, the company
when with a Hong Hua fan for the cooling needs of the HX850 unit. The double ball
bearing fan has a maximum speed of 2800RPM, which it will hopefully reach only
if pushed beyond limits as the PSU would be insanely loud with a fan rotating
anywhere near that speed.
The Corsair HX850 is based on a
Channel Well Technology (CWT) design, an OEM commonly used by the company to
manufacture their medium and high performance units. CWT designs are known for
their above average quality and performance, so no problems there. The
heatsinks of the HX850 however are worryingly small for a unit with such a
power output, with most being nothing more than a simple metallic slab with
minimal heat exchange surface.
CWT went with a “by the
book” transient filter, which starts at the back of the A/C receptacle and
continues onto the main PCB. In total, there are four Y capacitors, two X type
capacitors, two chokes and a MOV.
The base design of the HX850 is not
exceedingly complex, which is refreshing for an 80Plus Gold certified unit. It
does use a synchronous converter, which is more complicated than most other
converter designs, but the rest of the design is pretty straightforward. Two Nippon
Chemi-Con 420V/330uF capacitors can be found at the primary side of the unit,
both rated for operation up to 105°C, next to two plain heatsinks holding the
active PFC transistors. The primary switches of the power supply are on
another, yet also very simple heatsink with minimum heat dissipation surface.
Each and every electrolytic
capacitor on the secondary side is also being supplied by Nippon Chemi-Con; if
not for the exception of a few solid-state capacitors, Nippon Chemi-Con is the
manufacturer behind every capacitor in the HX850. The synchronous rectifier is
built on a secondary vertical heatsink which, to our surprise, is not attached
to a heatsink at all! The rectifier generates only a 12V rail. The minor lines
are generated by DC to DC circuits which are situated on the PCB holding the
modular cable plugs.