Seasonic G-Series 450W PSU Review

Seasonic's G series consists of reliable, high-performance PSUs. Today, we're reviewing the G-450 with 450W capacity, which features a semi-modular cabling design.

Seasonic is a well-known company in the PSU market; in addition to retail sales, its platforms are also used by many other companies, including Antec, Corsair, EVGA and Fractal Design. One of Seasonic's budget Gold-rated lines is the G series, which consists of five products with capacities ranging from 360 to 750W. Today we're looking at the G-450, which, as its model number implies, offers up to 450W of capacity.

All G-series power supplies use a semi-modular cabling design, have compact dimensions and are cooled by a 120mm fan. In addition, they are backed by a five-year warranty, which is rather long for the standards of this category. Seasonic claims that the performance of its G-series PSUs is top-notch, and we believe the company since we've tested a number of models in this line, including units based on the same platform. The results were very good in all cases.

The G-450 is a high-quality low-capacity PSU able to cover not only entry-level systems but also mid-range ones with respectable GPUs (thanks to its two auxiliary PCIe connectors). Power supplies like this are popular with enthusiasts who know they don't need massive output, only to use a fraction of it. Typically, lower-wattage PSUs achieve significantly higher efficiency at light loads compared with more powerful PSUs, so if your system's energy needs are low, then you should avoid buying a high-capacity supply. Otherwise, you'll pay more for the unit itself and incur increased operational costs compared to a less-powerful model offering the same efficiency characteristics. On the other hand, if you plan to add a second graphics card, you'll need a power supply with at least four PCIe connectors and 500W+ capacity. The G-450 would fall short in that case.


Besides 80 PLUS Gold efficiency, the G-450 is also Haswell-ready and can deliver its full power continuously at up to 50 degrees Celsius (122 degrees Fahrenheit) ambient temperature. This is a clear indication that it is based on a solid platform with good components that are able to withstand tough conditions. The PSU offers all necessary protections, including OCP (over-current protection), even though it sports a single +12V rail. We typically don't see OCP in PSUs with one +12V rail; Seasonic most likely added this protection because of the unit's low capacity.

Cooling is handled by a 120mm double ball-bearing ADDA fan. It's a good-quality cooler that should work flawlessly for many years. And even though the price is on the high side, we believe the build quality of this product justifies it.

Power Specifications

Max. PowerAmps20203730.3
Total Max. Power (W)450

The single +12V rail can deliver the PSU's full power alone; it has enough amperage to feed a high-end GPU. The minor rails are strong for a modern system that is covered by a 450W power supply, and the 5VSB rail has the typical capacity for a contemporary PSU.

Cables & Connectors

Modular Cables
DescriptionCable CountConnector Count (Total)
ATX connector 20+4 pin (550mm)11
4+4 pin EPS12V (570mm)11
Native Cables
6+2 pin PCIe (610mm)22
SATA (400mm+115mm+115mm+115mm)14
SATA (300mm+115mm)12
Four-pin Molex (400mm+120mm+120mm)13
Four-pin Molex (300mm+120mm)12
FDD Adapter (+110mm)11

This unit has the typical cable/connector configuration for a respectable low- to mid-capacity PSU. Seasonic equips it with a single EPS connector and a pair of PCIe connectors, through which the G-450 can easily deliver its full power. In addition, six SATA and five four-pin peripheral Molex connectors are more than enough for this category.

Overall, cable length is adequate with one exception: the EPS cable, which in our opinion should be at least 60 centimeters in length. All connectors use 18-gauge wires, which are recommended by the ATX spec.

Power Distribution

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

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