Specifications

With an efficiency of 80 PLUS Gold, the unit can deliver its max power continuously even at 50°C. The protections include all the usual ones except OTP (Over Temperature Protection), which, we believe, is crucial for a PSU. The cooling fan is equipped with double ball-bearings, so it will last pretty long and, finally, the PSU's length is much longer than the 160 mm usually seen.
The warranty period is very satisfactory at 7 years, while the price classifies the unit to the high-end category, where the competition is really tough. So the HX850 must perform very well in order to achieve a high price/performance ratio.

There is a single +12V rail that can deliver almost the unit's full power alone. This is very convenient for most users out there, since they won't have to bother about which cable/rail should be used for every component and, on top of that, modern systems are fed mostly by +12V. The minor rails are also pretty strong with 150 W max combined power, a power level that most likely won't be fully utilized by any contemporary system. Finally, the 5VSB can deliver up to 3 A, so it will easily cover most of the cases.

Cables & Connectors, Power Distribution

The PSU features numerous connectors including six PCIe and two EPS ones. However, at the same time, you can use either six PCIe and one EPS or five PCIe and two EPS connectors, something completely understandable if you take into account the unit's capacity.
The length of all cables is sufficient; however, the distance between the peripheral connectors is short, at only 100 mm. For SATA connectors, this may not be a significant problem, but for 4-pin Molex connectors it could cause trouble. Finally, the 24-pin ATX connectors use thicker 16AWG wires for lower voltage drops, while all other cables, except the FDD adapters, use the standard 18AWG gauges.

Since this PSU features a single +12V rail, we do not have anything to comment about its power distribution.