Specifications

For starters, efficiency is Platinum and the max operating temperature reaches 50°C. Only the basic protections are available, except for the rare Under Power Protection. We wanted to clarify on the features of this protection, to know all the details, but we haven't receive a response from the OEM Super Flower, yet. The cooling fan is very quiet since its max RPM is kept low and the unit's dimensions are not so compact, considering its small capacity.
Finally the warranty is set at three years, the usual period for this price range. Speaking of price, at 100 bucks the AP-550 is currently the most affordable Platinum unit. In comparison the Antec EarthWatts Platinum 650W costs $20 more but also offers 100W more power. Nevertheless our Performance per Dollar Graph will clearly indicate the winner between these two.

There is only a single +12V rail which can deliver the unit's max power on its own. This is very convenient of course, especially nowadays where all systems draw power mainly from this rail. The minor rails are restricted to 100W but you don't have to worry about this, since no modern system will need more. Finally 5VSB has the usual 12.5W capacity, which unofficially is the minimum power for this rail at least for a modern, decent quality, PSU.

Cables & Connectors, Power Distribution

Despite its small capacity the unit comes with four PCIe connectors and enough peripheral ones, so it will easily power a medium class system with two (not high-end) VGAs installed. Also the length of all cables is sufficient and the single EPS cable is really long at 70cm. It will provide compatibility even with large full tower cases, although we seriously doubt that a mainstream system will be ever installed in such a big case. Normally high-end systems are installed in full tower cases and 550W are not enough for the power hungry components of these systems. The distance among all connectors is the recommended one, by ATX spec of course and finally all cables use 18AWG gauges.

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