Building a compact ITX system requires careful component selection, and the power supply is often the most challenging choice. Standard ATX power supplies simply won’t fit in cases like the NR200P, DAN A4, or NCase M1.

SFX (Small Form Factor) power supplies are about 30% smaller than ATX units, measuring 125mm x 100mm x 63.5mm. They deliver the same power output in a compact package designed specifically for mini-ITX builds.

After building over a dozen ITX systems ranging from compact office PCs to powerhouse gaming rigs, I’ve learned that choosing the right SFX PSU involves more than just wattage. Cable length matters in tight spaces, fan noise becomes apparent in small cases, and not all “SFX” power supplies are actually SFX form factor.

This guide covers the best SFX PSUs for ITX builds in 2026, including budget options, premium ATX 3.1 compliant units, and everything in between. I’ve personally tested several of these power supplies in various ITX builds and analyzed hundreds of user reviews to bring you real-world insights.

Our Top 3 SFX PSU Picks

SFX PSU Comparison Table

The table below compares all SFX power supplies covered in this guide. Click “Check Price” to see current pricing and availability.

Detailed SFX PSU Reviews

1. Corsair SF750 (2024) – Gold Standard for SFX Power

The Corsair SF750 is widely considered the gold standard for SFX power supplies. I’ve used this PSU in three different ITX builds, and it has never let me down. The 2024 refresh adds ATX 3.1 and PCIe 5.1 support, making it future-proof for modern GPUs like the RTX 40-series and upcoming RTX 50-series cards.

What sets the SF750 apart is its Zero RPM mode. The fan doesn’t spin at all under low loads, making it completely silent for office work, web browsing, and media consumption. In my testing, the fan remained off even during moderate gaming sessions.

The 80 Plus Platinum rating means 92% efficiency at typical loads. This translates to less heat generation and lower power bills, both critical factors in cramped ITX cases where thermal management is a constant challenge.

Corsair includes 5 PCIe power connectors with 3 cables, giving you flexibility for multi-GPU configurations or graphics cards that require multiple power inputs. The native 600W 12VHPWR cable support means you’re ready for RTX 4090-class GPUs without needing adapters.

Customer photos show the SF750 installed in various ITX cases, confirming its compatibility with popular enclosures like the NR200P, Louqe Ghost, and custom open-frame builds. The compact dimensions (4.92 x 3.94 x 2.5 inches) ensure it fits even the most restrictive cases.

The main downside is cable length. The included cables are intentionally short for true ITX builds, which is great for compact cases but problematic if you’re using this in a larger chassis with an SFX-to-ATX bracket. You may need to buy extension cables.

2. Corsair SF850 (2024) – Maximum Power for ITX Enthusiasts

The SF850 takes everything great about the SF750 and adds 100 watts of headroom for truly power-hungry ITX builds. I recommend this unit for builders running RTX 4080, RTX 4090, or RX 7900 XTX graphics cards in compact cases.

With 850W of continuous power, you have enough capacity for overclocked CPUs and GPUs simultaneously. I’ve tested this PSU with an i9-14900K and RTX 4080 Super combination, drawing over 650W during gaming peaks. The SF850 handled it without breaking a sweat.

Like its smaller sibling, the SF850 features Zero RPM mode for silent operation at low loads. The fluid dynamic bearing fan is virtually inaudible even when it does spin up. User-submitted photos confirm the clean cable layout and compact dimensions that make installation a breeze.

The 80 Plus Platinum certification ensures excellent efficiency across the load curve. At 50% load (around 425W), this PSU achieves 92% efficiency, minimizing wasted energy and heat output.

Real-world customer images show the SF850 powering systems with flagship GPUs in compact cases like the Fractal Terra and NR200P. The 5 PCIe ports give you flexibility for dual GPU configurations or cards requiring multiple 8-pin connectors.

3. Lian Li SP750 – Best ATX 3.1 Value

The Lian Li SP750 V2 is one of the newest contenders in the SFX market, and it delivers exceptional value. It’s one of the most affordable ATX 3.1 compliant SFX PSUs, making it perfect for builders planning to use RTX 40-series or upcoming RTX 50-series GPUs.

What impressed me most about the SP750 is the native 12V-2×6 connector (the updated 12VHPWR). Unlike some competitors that use adapters, Lian Li includes a factory-made cable with visual cues to ensure proper connection. This eliminates the risk of melting connectors that plagued early RTX 4090 adopters.

The 92mm fluid dynamic bearing fan is designed for quiet operation. In testing, the SP750 remained virtually silent at loads up to 400W. Customer photos confirm the compact form factor fits easily in popular ITX cases.

Lian Li backs this PSU with a 10-year warranty, matching or exceeding competitors like Corsair and Seasonic. This shows confidence in the product’s reliability and gives you peace of mind for a decade of use.

The main limitation is that only 2 PCIe cables are included. Most RTX 4080/4090 cards require 3 or 4 cables for optimal power distribution. If you’re building with a flagship GPU, consider stepping up to the 850W version or buying additional cables.

4. Corsair SF600 – Legendary Reliability

The original Corsair SF600 has earned legendary status in the ITX community. With a 4.7 out of 5 star rating from over 1,100 reviews, it has one of the highest satisfaction rates of any PC power supply on the market.

I’ve personally built with the SF600 multiple times, and one unit has been running continuously in a home server for over 5 years without a single issue. The 100% Japanese capacitors and robust voltage regulation ensure stable power delivery even as the unit ages.

600W provides enough power for mid-range to high-end gaming builds. I’ve run systems with RTX 3080 and Ryzen 7 5800X3D on an SF600 without issues. However, it’s not recommended for RTX 4080/4090 or heavily overclocked systems.

Customer images showcase the SF600 in various case types, from the compact NZXT H210 to custom open-frame builds. The unit’s reputation for reliability is well-earned, with one reviewer reporting over 50 successful builds using this PSU.

The Zero RPM fan mode keeps things silent during light use. The fan only spins up when the PSU reaches higher temperatures, making it excellent for HTPC and living room builds where noise matters.

Buyer photos confirm the excellent build quality and premium feel of the unit. The sleeved cables are flexible enough for tight ITX cable routing, though some users report they’re on the shorter side.

The main drawback is that the SF600 lacks ATX 3.0 support and uses an older ATX 2.4 standard. It’s also becoming harder to find as Corsair transitions to the newer SF750/850 models. If you can find one at a good price, it’s still an excellent choice for builds without RTX 40-series cards.

5. SilverStone SX500-G – SFX Pioneer

SilverStone pioneered the SFX PSU market, and the SX500-G shows their expertise. When I started building ITX systems years ago, SilverStone was one of the few brands taking small form factor power seriously.

The standout feature of this PSU is the flexible flat cables. Unlike the stiff, braided cables on some competitors, SilverStone’s flat cables are incredibly easy to route in tight spaces. I’ve found this makes a huge difference in cramped ITX cases where every millimeter matters.

The 92mm fan is rated for 18 dBA minimum, making it one of the quieter options in its class. All Japanese capacitors ensure longevity, and the strict 3% voltage regulation provides stable power for sensitive components.

500W is sufficient for mid-range gaming builds with GPUs like the RTX 3060, RTX 4060, or RX 7600. I’ve used this PSU in a living room HTPC with an RTX 3060 Ti, and it handled gaming loads without issues.

Some users report coil whine, particularly when the PSU is under high load. This varies between units and can depend on your specific power grid quality. The current 23% discount makes this an attractive value if you can find a good unit.

6. EVGA SuperNOVA 450 GM – Best Budget Gold PSU

The EVGA SuperNOVA 450 GM offers premium features at a budget-friendly price. Despite being one of the most affordable fully modular Gold-rated SFX PSUs, it includes features typically found on more expensive units.

EVGA’s 7-year warranty is exceptional for a PSU in this price range. This shows the company’s confidence in the product’s reliability and gives you long-term protection for your investment.

The 92mm double ball bearing fan is designed for durability. Unlike sleeve bearings that can fail over time, ball bearings maintain consistent performance throughout the PSU’s lifespan. The ECO mode enables Zero RPM operation at low loads for silent operation.

100% Japanese capacitors ensure reliable power delivery and long-term stability. This is a feature often reserved for more expensive power supplies, making the 450 GM excellent value for money.

Customer photos show the compact size and clean layout of the unit. The fully modular design means you only use the cables you need, reducing clutter in cramped ITX cases. Real-world images from buyers confirm the build quality matches EVGA’s reputation.

The main limitations are the 450W capacity and short cable lengths. This PSU is best suited for compact cases where the short cables are an advantage rather than a limitation. It’s also becoming harder to find as EVGA focuses on higher-wattage models.

7. FSP 450W SFX – Cheapest SFX Option

The FSP 450W SFX is the most affordable entry point into SFX power supplies. It’s perfect for basic ITX builds where you don’t need gaming-level power but still require the compact SFX form factor.

This PSU includes a PS2 bracket for installation in standard ATX cases, adding versatility. I’ve used this unit in office PC builds and home theater systems where the budget was tight but an SFX PSU was required.

The 80mm intelligent fan adjusts speed based on temperature, balancing cooling and noise. At under $80, this is about as cheap as SFX power supplies get while still coming from a reputable manufacturer.

Customer images show the unit installed in various ITX cases, confirming compatibility with popular enclosures. The black ribbon cables look decent despite being non-modular, though cable management will be more challenging without the ability to remove unused cables.

450W with 80 Plus Bronze efficiency is adequate for office PCs, home theater systems, and very light gaming. I wouldn’t recommend this for any system with a dedicated graphics card more powerful than a GTX 1650.

Real-world photos from customers validate the compact dimensions and basic build quality. User-submitted images show the PSU in working systems, confirming it can handle basic computing tasks reliably.

SFX vs SFX-L vs ATX: Form Factors Explained

Understanding form factors is critical when building ITX systems. I’ve seen builders mistakenly purchase ATX power supplies that simply won’t fit in their compact cases.

SFX-L offers a significant acoustic advantage with its 120mm fan. The larger fan spins slower to move the same amount of air, reducing noise. In my experience, SFX-L PSUs are noticeably quieter under load, making them ideal for living room builds.

However, SFX-L compatibility is case-dependent. The extra 25mm of depth can interfere with front panel connectors or drive mounts in some ITX cases. Always check your case specifications before choosing SFX-L.

How Much Wattage Do You Need?

Choosing the right wattage is critical for system stability. After seeing multiple systems crash under load due to inadequate power supplies, I always recommend building in headroom.

Modern graphics cards from Nvidia and AMD experience transient power spikes that can exceed their rated TDP by 200-300% for milliseconds. The RTX 4090, for example, can spike to over 600W even though its rated TDP is 450W.

I learned this lesson the hard way when a client’s system with RTX 3080 and “just enough” wattage PSU kept crashing during gaming. Upgrading to a higher wattage unit solved the problem immediately.

ATX 3.0, ATX 3.1 & PCIe 5.0 Explained

ATX 3.0 and the newer ATX 3.1 are essential for RTX 40-series graphics cards. These cards use a new 12VHPWR (or updated 12V-2×6) connector that can deliver up to 600W through a single cable.

Older power supplies require an adapter to work with these GPUs, which introduces a potential point of failure. ATX 3.0/3.1 PSUs include native cables designed specifically for these power-hungry cards.

For 2026 and beyond, I recommend ATX 3.1 compliance if you’re planning to use RTX 40-series or RTX 50-series GPUs. The improved 12V-2×6 connector includes visual cues to ensure proper seating and additional sensing pins to prevent the melting issues that affected some early adopters.

PCIe 5.0 support often goes hand-in-hand with ATX 3.0, but it’s primarily about the graphics card interface rather than power delivery. For PSU selection, focus on ATX 3.0/3.1 compliance rather than PCIe generation.

Frequently Asked Questions

Final Recommendations

After extensive research and real-world testing across multiple ITX builds, I recommend the Corsair SF750 for most builders seeking the best balance of performance, acoustics, and future-proofing. Its legendary reliability, Zero RPM silent mode, and ATX 3.1 compliance make it the safest choice for 2026 and beyond.

Budget builders should consider the EVGA SuperNOVA 450 GM for its 7-year warranty and fully modular design at an affordable price. For those needing ATX 3.1 compliance without breaking the bank, the Lian Li SP750 offers excellent value with native 12V-2×6 support.

Remember that the Seasonic Focus GX-750, despite appearing in searches, is an ATX power supply and will not fit in ITX cases requiring SFX form factor. Always verify compatibility before purchasing.