We would like to thank Seasonic for supplying the review sample.
The G series is currently Seasonic’s second most affordable series after the S12G line. It includes four members with capacities ranging from 450 W to 750 W. Some of you will remember our G-550 model review only to wonder what the point in testing the unit again would be. The reason is simple as Seasonic recently silently upgraded some of their G series units, terminated the 360 W model, and introduced a new 750 W model. A quick look at the model numbers and all its crucial specifications shows that those remained the same. The only noticeable difference is the Haswell compatibility badge on the package itself, which doesn't mean much since the older units featured DC-DC converters and were Haswell ready. Seasonic simply sought to highlight the fact and took the opportunity to do so to make a few internal changes we will detail in the following pages.
The G-550 unit we will evaluate today is 80 Plus Gold certified, features a semi-modular cabling design, and is pretty compact. It also uses a ball-bearings fan, which will last longer, and doesn’t include a semi-passive operation, which is contrary to the high-end Seasonic units that go fanless at low loads. This PSU is essentially destined for a mid-range system with a single VGA or two low-end ones because it only comes with two PCIe connectors and relatively low capacity. We know that four PCIe connectors can often be too much for a 550 W unit if you, for example, try to feed two AMD R9 280X VGAS, but anything less should run so long as you don't overlock anything. However, Seasonic made a point of playing it safe in order to avoid situations where a user might try to run a configuration not meant to be run by a 550 W PSU. Judging by the performance of the previous G-550 model, our expectations are high for its new iteration, but we will have to wait for our test results to see whether those expectations will be met.