Seasonic FOCUS SGX-450 450W SFX-L PSU Review

Author:Paul Johnson

Editor:Kyle Bennett

Date: Monday , December 31, 2018

Seasonic is delving deeper into the small form factor end of the power supply pool with its new FOCUS SGX. The SGX-450 has a 125mm x 125mm footprint, is supplied with an ATX adapter bracket, is fully modular, carries Gold efficiency certification, and comes with Seasonic's rock solid 10 year warranty.


The first thing we are going to look at with the FOCUS SGX-450 is the packaging, accessories, and documentation. While normally none of these items is a make or break item for a power supply the packaging quite often contains a lot of information about the product we are purchasing. The inclusion of an owner’s manual that provides actual information about our product is also of great help. Accessories are almost unnecessary with a power supply as the unit is self contained, unless it is modular, but there are cases where a manufacturer can include useful accessories to make installation, routing, and use more efficient.

The packaging of the FOCUS SGX-450 is different from everything else we have seen in the FOCUS line of power supplies to date. Today, we (obviously) have much smaller packaging but also a different layout and composition as well. The front of the packaging simply has the brand, product line, model, capacity, a couple of advertising points (about modular nature and fan control), a listing for a 10 year warranty, and an 80 Plus Gold sticker. This is all on a black background that has an interesting stripe pattern made up of various silver/gold stripes. Among those points above, the only item worth investigating is the 80 Plus Gold seal and, when we do, we see that the 80 Plus website shows that this unit is indeed certified for 80 Plus Gold levels of efficiency (how it actually performs is something we will see shortly). When we flip to the rear of the packaging, we find a bunch of advertising about today's unit including voltage regulation, efficiency, fan type and design, etc. We also find the 10 year warranty listed here again. As we have noted before, this is a particularly long warranty given that these FOCUS PLUS units are not flagship products. Moving on to the sides of the packaging, we find the power label (reproduced below) and the connector count (reproduced below).

Today's FOCUS SGX-450 power and connector distributions are about what we would expect from a modern 450W SFX unit. The 12v rail capacity is up to 37A (or ~99% of the unit's capacity) if necessary. The minor rails (5v and 3.3v) each have a capacity of 20A and the combined capacity of those two rails is 100W. Combined with these outputs, we find that each unit has two PCIe connectors, three SATA connectors, and three Molex connectors. Given that this unit is going to be living, most of the time, in very small form factor cases these cable counts (and the lengths we see associated with them in a bit) are about right.

Once we open the FOCUS SGX-450 packaging, we are left looking at the power supply itself, a power cord, some screws, the modular cables in a pouch, some zip-ties, an ATX adapter plate, and the user manual. The user manual is 15 pages long in 12 languages. Unfortunately, all we find in the manual is a small section on the warranty and a few troubleshooting steps that basically amounts to make sure the unit is plugged into power and your PC and then turn it off and on again. It is kind of terrible documentation all things considered, or anything considered. We got the ATX adapter plate though! Let's move on to look at this unit by itself now.