Introduction

We would like to thank Silverstone for supplying the review sample.

About two years ago, Silverstone released the ST45SF, which was a milestone in the SFX category because it packed a high capacity for its category and was, on top of that, able to deliver its full power at up to 50°C. Recently, Silverstone released another SFX PSU: the ST45SF-G. It comes with many upgrades including the 80 Plus Gold certification and a fully modular cabling design. The only area that their new model straggles behind in is the maximum operating temperature at which it can deliver its full continuous power which dropped to 40°C from the 50°C of the ST45SF, but we will still test at higher ambient to see how it performs.

The new ST45SF-G faces minimal competition in the SFX category, and the only worthy opponent is its older sibling. According to Silverstone, the ST45SF-G is an important milestone for DIY desktop computers since it offers features that were never available in the SFX category. This is, to the best of our knowledge, the only Gold SFX PSU with fully modular cables, which is amazing if we take into account how compact the unit is. The ST45SF-G offers, besides its high capacity, a tight voltage regulation on all rails. Silverstone also promises low ripple on all outputs. The PSU is also equipped with two PCIe connectors and can, as such, feed a strong small-factor system equipped with a high-end graphics card. Its small footprint doesn't allow for a cooling fan larger than 80 mm, but the fan is, according to the product's official description, silent and puts out a minimum of 18 dBA. Well, we would like to know its maximum output noise, and we will provide you with the fan's speed at various load levels in this review, which should give you a good picture of its noise output.

Specifications

Efficiency is compatible with 80 Plus Gold, and the maximum operating temperature dropped to, unfortunately, 40°C from the 50°C of the older ST45SF. Its protection features even include OTP (Over Temperature Protection) which we think of as crucial for an SFX PSU that will operate in cases with minimal air-flow.

The cooling fan is restricted to an 80 mm diameter since a larger one couldn't fit into this PSU. It is a ball-bearing fan, and will, as such, last longer than a sleeve-bearing fan. The PSU's dimensions are really compact since the ST45SF-G is an SFX PSU, but its weight isn't that light, which indicates that its heatsinks are quite big.

Strangely enough, Silverstone states that this PSU is compliant with ATX v2.31 which requires at least two +12V rails, while this PSU has a single +12V rail. Finally, the PSU's warranty is set to three years and its price is a bit stiff, but the ST45SF-G is the only player in its field. It practically has no competition in its category.


This little guy packs a strong +12V rail that can deliver almost its full capacity, while the minor rails are restricted to 90 W - a power level which, however, is more than enough for a typical system. Finally, the 5VSB rail has the minimum allowed capacity for a modern PSU.

Cables & Connectors, Power Distribution

All cables are modular, something that will be greatly appreciated by most users. Since this PSU is intended for a small chassis, all of its cables are inevitably short; however, the distance amongst connectors is pretty large. Also, the number and type of available connectors is the same with the ST45SF unit and will most likely cover the needs of a small/medium system. Nevertheless, we would like it to feature at least a couple more SATA connectors.

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

Packaging

The box is very small, which makes sense since it houses a compact PSU, but it features vivid graphics with an emphasis on the color gold to highlight the unit's Gold efficiency. On the front, we find the 80 Plus Gold badge, a photo of the PSU, the model and capacity description, and a features list.


Some of the PSU's specifications and a power specifications table are given on one of the two sides. On the other side, available connectors are illustrated. The first sample we had was V1.0 but later Silverstone send us a new sample, V1.1, which addresses some problems that they noticed and have to do with increased ripple on the minor rails. All of our tests were conducted with the newest sample (V1.1) in which the main difference from the older one is that on a wire of the ATX modular cable a capacitor was added, to increase capacitance.


The rear side has several illustrations showing the efficiency curve, the modular panel, the strict regulation and low ripple of the rails, and, finally, the single +12V rail that this unit features.