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Power supplies come in various sizes. SFX types are used in compact computers and are smaller than the typical ATX ones, making them potentially hotter and louder. While SFX models aren’t as popular as regular ones, there’s a growing variety due to increased interest in compact builds. We’re diving deep to highlight some of the best SFX power supplies available, ranging from 450W to 850W. As mentioned in our best 600-650W PSUs and the best 700-750W PSUs lists, quality is more important than just power. We’ll suggest both budget and premium options for each category. Also, for those keen on compact builds, see our best Mini-ITX cases. Let’s dive in!
The budget SFX PSU bracket offers affordable, quality models, with 450W and 500W units suitable for entry to mid-level gaming. FSP, often an unseen OEM for brands like SilverStone and EVGA, has its own FSP Pro SFX line, offering value with an 80 Plus Bronze rating. Their 450W model, cooled by an 80mm fan, is ideal for quieter, cooler budget gaming in high-airflow Mini-ITX cases.
That being said maybe you should check out our list of the best airflow PC cases. However, a significant downside to the FSP Pro 450W SFX is its non-modular design. Nevertheless, it’s a robust entry among the best SFX power supplies for budget-conscious, compact builds.
2. Corsair SF450 Platinum: Best overall 450W SFX PSU
For the cream of the crop in best SFX power supplies, Corsair’s SF Platinum series stands unbeaten, boasting superior components and full modularity. The entry-level 450W model is efficient with a 92mm fan. Performance-wise, it excels in load regulation and ripple suppression, maintaining low noise levels, capped at 35Db(A). Impressively, it comes with a seven-year warranty. The Corsair SF450 Platinum’s premium pricing can be offset by opting for the slightly less efficient 80 Plus Gold variant, which is more affordable but still delivers excellent performance.
3. EVGA SuperNOVA 550 GM: Best budget 550W SFX PSU
For enthusiast SFF PCs with mid to high-end components, the 550-600W range is optimal. Among two notable models, one offers affordability without compromising on quality, while the other stands as the top pick in this bracket.
The EVGA SuperNOVA 550 GM is a commendable SFX PSU, boasting an 80 Plus Gold rating. Its 650W variant performs impressively with minimal noise, suggesting the 550W would follow suit. It excels in load regulation, ripple suppression, and maintains safe temperatures even under stress. The fully modular unit comes with ample cables for any GPU and offers a seven-year warranty, all at a competitive price. A top choice for those seeking a reliable SFX PSU without breaking the bank.
4. Corsair SF600 Platinum: Best 550-600W SFX PSU on the market
The SF600 Platinum is the best SFX power supply in the 550-600W tier, period. There’s no better choice than this one. Yes, it’s expensive (about 50 to 60 percent higher than the SuperNOVA 550 GM), but it delivers the best performance in the class.
It’s also relatively silent and has top-notch efficiency. Measurements such as load regulation and ripple suppression are also best in class. A fully modular design is the standard at this price point, and you also get a seven-year warranty. Finally, there’s the SF600 Gold version on the market that sells for noticeably less.
Venturing into the elite realm of best SFX power supplies, tailored for elite gaming setups. Given the challenge of packing immense power into such a compact size, budget options are absent in this tier.
The Seasonic SGX-650, from their mid-range Focus Gold line, offers superb value. This fully modular PSU stands out for its stellar performance and quiet operation, even under stress. With an 80 Plus Gold efficiency and a generous ten-year warranty, it’s a cut above many. Its low noise and optimal temperatures are attributed to a 120mm fan, designating it as an SFX-L unit. Being slightly larger than standard SFXs at 125 x 125 x 63.5 mm, it fits most Mini-ITX cases, but do ensure compatibility before purchasing.
If your case doesn’t fit an SFX-L, consider the EVGA SuperNOVA 650 GM. More compact and affordable than SeaSonic’s SGX-650, its performance is similarly high. Quieter than the Corsair SF600 under load, it operates in semi-passive mode until 120W. With a commendable seven-year warranty, it’s ideal for demanding SFF builds.
7. SilverStone NJ450-SXL: Best passive high-end SFX PSU
If you want to build a silent small factor build and want a passive SFX power supply, there’s only one model that fits the bill. It’s the NJ450-SXL from SilverStone. If you need recommendations for a quiet PC case, our list of the best quiet PC cases includes a number of whisper-quiet enclosures.
The NJ450-SXL is a sleek, fully modular SFX-L PSU, sporting black aluminum heatsinks that unfortunately won’t be showcased in most builds. With dimensions of 125 x 130 x 63.5 mm, its bulk and weight exceed other SFX power supplies, projecting a robust aura.
Its distinct feature is the absence of a cooling fan, ensuring silence. However, in environments over 40°C, it can’t maintain 100% load, and prolonged stress may cause shutdowns. In cooler settings, it boasts an efficiency aligning with its 80 Plus Platinum certificate, staying under 42°C even at full load.
With top-notch load regulation and ripple suppression, its three-year warranty is a bit short. Priced similarly to the Corsair SF750, it’s a premium choice for those prioritizing silence in compact builds.
Packing 750W into an SFX frame is remarkable, and for those needing such power in a compact form, the Corsair SF750 Platinum stands alone. It’s crafted from top-grade materials, offering stellar efficiency and performance. While its load regulation slightly trails the SF600, its ripple suppression is unmatched among SFX PSUs.
The unit remains quiet until 300W, impressive for its size. At full capacity, it can hit 40Db(A), but typically stays below 30Db(A) under average loads. Backed by a seven-year warranty, it does come at a premium, but it’s the undisputed best in its class.
9. Cooler Master V850 SFX Gold: Most powerful SFX power supply on the market
In the realm of high-powered compact units, there are now two true SFX 850-watt contenders vying for the title of best SFX power supplies: the Cooler Master V850 SFX Gold and the EVGA 850 GM. Both seamlessly fit any ITX case, with the Cooler Master model offering a more affordable price point. Impressively, both units boast the 80+ Gold certificate.
The V850 stands out with its impressive efficiency and performance for its size. Although louder, its fan remains off until reaching around 15% load, ensuring quiet operation during basic tasks like web browsing. Built from quality components, it promises durability and safety. Initial batches had fan noise issues, but recent models have rectified this. However, the provided cables are somewhat short, which might be problematic for larger ITX cases.