The Chieftec Atmos 850 W PSU shows a very respectable mid-tier PSU performance without breaking the bank. It is no way flashy and won't win any design awards with its cables, but that's fine. For its main purpose, the Atmos 850 W delivers a very solid performance. It offers 80 Plus Gold efficiency levels and supports ATX 3.0, which, given the fact that the PSU typically outlives the remaining components when upgrading, should definitely be on the requirements list for people purchasing anything but a basic office rig.

While we have definitely seen more well controlled voltage regulation on other power supplies, the results of the Atmos 850 W are nothing to complain about. What does seem like a very small yet significantly annoying feature of the PSU is the fan tuning profile. While the supply is using a quality fan, it leaves us wondering whether a more conservative tuning wouldn't be sufficient to keep the PSU running cool enough even at higher loads.

The market has quite a few alternatives to offer in the ~800 W PSU segment with similar specifications. When considering alternatives, the similarly specced and priced Thermaltake GF A3 series comes to mind. And so does the more expensive Seasonic Focus V3 series or the FSP Hydro G Pro.