Articles

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.
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Load Testing

For those of you that are curious as to some of the reasoning and equipment behind our PSU testing program here at HardOCP, we have put together a living document that shares a lot of the behind the scenes of the program. The testing we are conducting today is exactly as described in that document and will begin with a range of loads tested at 120v input including our torture test and then move on to the same set of tests at 100v input but without the torture test.

120v Load Testing Results

Test #1 is equal to approximately 25% of the rated capacity of the FOCUS SGX-450 at 45c. This makes Test #1 equal to 123W by loading the 12v rail to 8a, the 5v rail to 2a, the 3.3v rail to 1a, the +5vsb to 2a, and the -12v to 0.3a. The results of Test #1 show the main positive DC output rails starting off above nominal on the positive rails except for one 12v connector. The efficiency for this unit is starting off today at a value of 85.92% and an exhaust temperature that is not yet registering.

Test #2 is equal to approximately 50% of the rated capacity of the FOCUS SGX-450 at 45c. This makes Test #2 equal to 227W by loading the 12v rail to 16a, the 5v rail to 3a, the 3.3v rail to 2a, the +5vsb to 2a, and the -12v to 0.3a. Test #2 sees mixed changes in DC output voltages relative to what we saw with Test #1. The 3.3v and one connector on the 12v rail have dropped by 0.01v while the balance of our main DC outputs have stayed even with Test #1's values. In addition to this, the efficiency has moved up to 89.54% while the exhaust temperature is coming in at 50C.

Test #3 is equal to approximately 75% of the rated capacity of FOCUS SGX-450 at 45c. This makes Test #3 equal to 337W by loading the 12v rail to 24a, the 5v rail to 5a, the 3.3v rail to 3a, the +5vsb to 2a, and the -12v to 0.3a. Test #3 sees the 5v and 3.3v rails match Test #2's values. The 12v rail has also mostly remained even with Test #2 values or increased by 0.01v depending on the connector you look at. The efficiency in Test #3 moves down to 89.39% while the exhaust temperature has risen to 53C.

Test #4 is equal to approximately 100% of the rated capacity of the FOCUS SGX-450 at 45c. This makes Test #4 equal to 449W by loading the 12v rail to 34a, the 5v rail to 4a, the 3.3v rail to 2a, the +5vsb to 2a, and the -12v to 0.3a. In the final regular test, we see the 12v rail rise by up to 0.03v. The minor rails, however, drop by 0.01v (5v) or stay even with Test #3's values (3.3v). The efficiency has dropped in this test as we see it settle at 88.26% and the exhaust temperature is 56C.

Load Testing Summary

The FOCUS SGX-450 starts the day off in truly outstanding form. The voltage regulation saw a peak change on the 12v rail of 0.03v while the 5v and 3.3v rails saw peak changes of just 0.01v! Wow! Given those absolute results we could, or maybe should, skip the relative performance results as they likely do not matter and are simply a waste of paper. Well, not paper since this is a website and, well, in that case we aren't actually wasting much doing the relative comparison. So, here goes. Among the few SFX and SFX-L units we have seen that also are 450W units, the FOCUS SGX-450 bests the SilverStone NJ450, SilverStone ST45SF V3.0, and SilverStone ST45SF-G. Which makes this the best unit we have seen in this regard among this group and it wasn't even a close competition to say the least. Now, when we move on to the efficiency side of things, we see that the FOCUS SGX-450 ranged from 85.92% to 89.54% efficient at 120v AC input. Those efficiency values are very good, but they seem a bit lower than what we would expect from an 80 Plus Gold unit. However, we have not run those tests yet so we will defer judgment for now except to say that this probably could have been a bit better. Let's move on to the 100v tests to see how this unit can continue to just destroy the voltage regulation there.