Specifications

This PSU's efficiency is Gold, its capacity is medium, and it is, as the ATX spec recommends, able to operate at 50°C. All available protection features for desktop PSUs, including the essential Over Temperature Protection (OTP), are present inside the G-550.
The fan that cools down the unit has a 120mm diameter and is equipped with ball-bearings for increased lifespan. The G-550 has normal dimensions for its capacity and will easily fit in every chassis that takes ATX PSUs. Finally, the provided warranty is set at five years, which is a pretty long period. The G-550, although it is considered cheap for a Gold Seasonic PSU, still meets some strong competition from, mainly, Rosewill Capstone units because of its price-tag.


There is only one +12V rail that can output almost the unit's full power, which is really convenient for contemporary systems that draw most power from this rail. The minor rails are set at 100 W max combined, which is a sufficient power level for a medium capacity PSU. The 5VSB rail can deliver the standard 2.5 A; the minimum current output we meet in today's PSUs at this rail.

Cables & Connectors, Power Distribution

The main downside of the G-550 is the existence of only two PCIe connectors which greatly restricts the PSU's usability. We think that Seasonic should provide the G-550 with four PCIe connectors in order to be able to support two GPUs with dual-power connectors each. On the other hand, they probably didn't want to create internal competition with their X-560 unit that features two PCIe connectors as well. Since the PCIe cables are modular, the addition of two more connectors is a relatively easy process that would only increase the cost of the PSU slightly while, at the same time, highly increasing its usability. The unit does, thankfully, come with enough SATA and peripheral connectors for its capacity.
As the above table shows, there are only two native cables. The EPS cable is relatively short and could cause trouble in a large, full-tower chassis, but a large chassis is usually intended for high-end systems with lots of components, and the G-550 wouldn't suit such a system even if it had a longer EPS cable. The SATA and peripheral cables come in two sets. One has more connectors with a longer distance up to the first connector, and one has fewer connectors on a shorter cable. This is very convenient and will make cable-management tasks easier. Finally, all connectors use 18AWG gauges which is, according to the ATX spec, the minimum requirement for the primary rails.

We do not have anything to comment on about its power distribution because this PSU feature a single +12 V rail.