The SX1000 is the strongest small form factor PSU on the market today, and in reality, it is way stronger than its paper specs since we pushed it up 1480W. This is 148% above its nominal capacity! Enhance, the OEM behind this platform delivered a solid unit to SilverStone, with quite good build quality and top-notch parts.
This is also shown by the provided warranty, which at five years is pretty long, given this unit's insane power density score. In other words, the SX1000 is a small, only in dimensions, power factory, able to support everything you throw at it. With some small improvements, it can be way better. We would like to see a properly working over-temperature protection, better ripple at 12V, lower turn-on voltage at 5VSB, and a lower Power-On time.
The competition in this 1000W small form factor category is non-existent since, so far, the SX1000 is the only PSU of its kind. We are not sure if more brands will follow SilverStone's path and release such strong SFX-L units, something that would make Enhance Electronics happy since, so far, it seems to be the only one having such strong small form factor platforms.
In the SFX-L form factor, the only alternative is the lower-capacity SilverStone SX800-LTI, which has Titanium efficiency and higher overall performance. However, both the SX1000 and SX800-LTI have high price tags, especially in the US market where there are extra fees, so they do not address most users but only those who need such high power density.
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Disclaimer: Aris Mpitziopoulos is Tom's Hardware's PSU reviewer. He is also the Chief Testing Engineer of Cybenetics and developed the Cybenetics certification methodologies apart from his role on Tom's Hardware. Neither Tom's Hardware nor its parent company, Future PLC, are financially involved with Cybenetics. Aris does not perform the actual certifications for Cybenetics.
If you want to stay around 50% load for max efficiency then this needed. Especially when people cram like a 3090 and a 5950x/ into an ITX with custom water cooling and stuff just because they can. Alternatively they might be a modder where they need the smaller PSU for some reason. Definitely a niche product though.
Nearly silent PSU, by the way.