Specifications

Efficiency is Platinum certified, and the unit can deliver its max power continuously even at 50°C. Regarding the protection features, almost all are present except the rare OTP (Over Temperature Protection) which is always nice to see. Also, the unit's dimensions are similar to the regular ones and its weight is acceptable too for a 550 W PSU.
Strangely enough, Rosewill claims that the Fortress 550 W is ATX v2.31 compliant; however, this cannot be true since this ATX version requires at least two +12V rails and the Fortress is equipped with only one. Nevertheless, this is a minor issue and was probably glossed over by Rosewill. Finally, the warranty is very long, seven years, which proves that this is a highly reliable product but does not come on the cheap.


As mentioned, the PSU is equipped with a single +12V rail which can deliver almost the unit's full power alone. This is very convenient nowadays such that all systems heavily utilize this rail, unlike the minor rails that are used by some devices with low-power needs. So the max 100 W combined output of this unit on the minor rails will fully cover most likely all modern systems, while the 5VSB rail has the typical capacity of a contemporary PSU of this category.

Cables & Connectors, Power Distribution

Rosewill decided that only two PCIe connectors are necessary for this unit, which is unfortunate since this significantly affects its usability. We are pretty sure that a 550 W PSU can easily handle four PCIe connectors, especially if it is based on a good platform like this model. Thankfully, there are enough peripheral connectors for the capacity of the unit.
All cables have sufficient length, and the distance between all connectors, on cables that have more than one, is adequate. Also, most of the connectors use 18AWG gauges, which are the right ones according to the ATX spec, while the first PCIe connector and the single EPS connector use 16AWG gauges. Also, the +12V wires of the main ATX connector have a size of 16AWG.

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