Power Supply Quality

As part of our testing, we also check output parameters are within specifications, as well as voltage ripple and line noise.

Main Output
Load (Watts) 202.65 W 505.85 W 753.59 W 1001.78 W
Load (Percent) 20.27% 50.58% 75.36% 100.18%
  Amperes Volts Amperes Volts Amperes Volts Amperes Volts
3.3 V 2.27 3.39 5.66 3.39 8.5 3.33 11.33 3.31
5 V 2.27 5.13 5.66 5.08 8.5 5.06 11.33 5.01
12 V 15.1 12.14 37.75 12.13 56.62 12.05 75.5 12.02


Line Regulation
(20% to 100% load)
Voltage Ripple (mV)
20% Load 50% Load 75% Load 100% Load CL1
3.3V + 5V
3.3V 2.1% 12 20 22 26 18 22
5V 2.25% 18 26 30 34 20 26
12V 0.92% 16 32 46 78 76 30

The electrical performance of the SilverStone SX1000 is good and within our expectations for an Enhance platform. Line filtering could use some improvement, as the voltage ripple figures are relatively high, with our instruments recording a maximum of 78 mV, 34 mV, and 26 mV on the 12V, 5V, and 3.3V lines respectively. These figures are adequate, but top tier units easily halve these values. Meanwhile line regulation is significantly better, with the 12V line maintaining a regulation factor of 0.9%. The regulation of the 3.3V and 5V lines is a little higher than 2%, which is enough for a modern design.


Unlike ATX PSUs, SFX designs have still seen significant development over the past few years. Not only has their power output increased considerably, but their overall performance dramatically improved as well. SilverStone is a company strongly focused on the R&D of small form factor cases (SFF), systems, and other related parts. They have several compact cases and products designed for high-end living room systems, including designs that were designed with gamers in mind. Therefore, their efforts to market the very best SFX PSUs available are not unfounded. The SilverStone SX1000 is a noteworthy milestone as it has a tremendously high-power density, delivering power that it would be difficult for a physically larger standard ATX unit to deliver about a decade ago.

While the SX1000 is, for the moment at least, the most powerful SFX/SFX-L unit on the planet, its overall performance left us with mixed feelings. In some ways it feels as if it is a small step back from the SX800-LTI, a unit that delivered better energy conversion efficiency and power output quality. The electrical performance of the SX1000 is not bad at all – it does meet all 80Plus Platinum certification and quality standards with ease – it is just a little worse than its less powerful predecessors. It also struggles to maintain reasonable noise and temperature levels when the load is very high, even when the operating environment is relatively cool. However, due to the possibility of high internal temperatures, the designer is using very high-quality components so that they will not be thermally stressed. This bodes well for the quality and longevity of the SX1000, as these components will perform very reliably under normal operating conditions.

Much like most top-tier SFX units, the SX1000 is struggling to find its identity in the retail market. Its SFX-L design limits its compatibility with SFX cases and there is no adapter to install it inside an ATX-compliant case either – in which case, the length of the cables could be a problem. It is powerful enough and has enough connectors to power a top-tier motherboard and two graphics cards, yet such motherboards and two cards will not fit in the vast majority of SFX-L compliant cases. Only an SFX case designed to hold a top-tier Micro ATX motherboard and four slots' worth of graphics cards would be a reasonable match for the SX1000.

The creation of a powerful gaming small form factor PC for the living room is the heartfelt desire of every serious gamer. Still, few are determined (and deep-pocketed) enough to be able to justify an aesthetically elegant and compact gaming PC with a flagship graphics card in it. Nevertheless, SilverStone’s latest PSU is designed to specifically target that small, yet existent, segment of the market. More pragmatically, perhaps, it could also be used to power systems with a single high-end graphics card while operating near its half capacity, offering top efficiency and reliability. However, the very high retail price of $366 at this writing severely limits the market potential of the SX1000, as only users who do not care about having a budget when building a PC would purchase it. 

Hot Test Results (~45°C Ambient)
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  • CheapSushi - Thursday, July 29, 2021 - link

    I wish tech sites and people would stop talking about SFX as if it shouldn't just be the standard PSU already. SFX and SFX-L should be every new modern PSU. 1000W shouldn't be surprising. It should be "why do you need 1000w SFX PSU". It should just be the norm of what to expect options wise. Why do we still want huge massive bricks? The entire industry is improving. It's like ignoring M.2 form factor because 3.5" HDDs exist. Why do you need a smaller had drive? See, sounds ridiculous. The same could be said about laptop chargers. They're finally getting smaller on average. Why can't we embrace SFX and SfXL as the norm. The more that is made, the cheaper it gets. The level evens out on price parity with legacy sizes. There are case adapters too. It just makes a huge amount of sense. Even in a big case, you still save volume. I'm using SFX in a Rosewill 4U for example. The adapter from Silverstone gives it more air vents in the same space. It's great. It's nothing unusual. Plus another thing with higher watts is it's the only way to get more SATA power ports.
  • whaletail - Sunday, August 1, 2021 - link

    Considering this is the first 1000W SFX-L PSU to market, doesn't seem like the market's ready for an SFX/SFX-L norm yet. As more consumers/enthusiasts demand smaller PSUs, which doesn't seem far-fetched, more momentum will develop in that direction, but we're not there yet.
  • Oxford Guy - Wednesday, August 11, 2021 - link

    ‘doesn't seem like the market's ready for an SFX/SFX-L norm yet’

    Umm... what reality is ready for is wattage that conforms to the laws of physics in a practical manner.
  • Oxford Guy - Wednesday, August 11, 2021 - link

    That said... better heatsinks may have helped. Better efficiency (‘titanium’). A better fan.

    Most importantly, though... not using power pigs like Rocket Lake and thus having no need to try to stuff 1000 watts into a small form factor.
  • easysteelchina - Friday, August 13, 2021 - link

    EasySteel China is a Leading China Hastelloy blend supplier .
    We believe in credit and quality first. we offer in an assortment of approaches including pipe fittings,
    bar, sheet, expansion joints. wire, plate, forgings, and a short time later a few.<a href="https://easysteelsh.com/project/plate/">Ch... rolled clad plate</a>
  • besterino - Tuesday, August 24, 2021 - link

    This is the only SFX PSU actually able to power a (read: one) 3090 GPU.

    A couple of months ago I built a watercooled 5800X+3090FE system in a DAN A4 case (wiith external radiators, will not discuss "y tho?") and the Silverstone SX800-LTI PSU shut down consistently in various games, if I did not limit the power limit on the 3090 to ~80%. When I put this 1000W PSU in, all problems gone.
  • Fuckman4 - Monday, August 1, 2022 - link

    I don't know why all Silverstone PSUs have a high ripple even in Titanium models!
    I have to wait for ROG LOKI for reasonable output quality.

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