What PCs are compatible with SFX form factor power supplies?

What is an SFX power supply?

SFX PSU, or Small Form Factor it’s a compact power supply type, designed for small PC cases. Their size is smaller than the standard ATX, approximately 125 mm ×100 mm × 63 mm. Such dimensions allow you to install it in different small cases – Mini-ITX or HTPC. 

Despite its small size, the latest SFX power supply can produce 450–800 W and more. They are also equipped with a full modular design due to the limited space inside the mini cases. Overall, SFX PSUs allow you to build a powerful PC in a small case without sacrificing system stability and security.

How does it differ from standard ATX models?

A standard ATX PC power supply is a bit larger than the SFX version. Every part of it is compact – it’s thinner, lower, and shorter (125 mm ×100 mm × 63 mm). SFX is primarily designed for small Mini-ITX cases, while ATX is designed for medium and large cases. In terms of power capacity, SFX typically produces 300–800 W; ATX can offer higher ratings (1000–2200 W). SFX are often fully modular or have shorter cables for compact builds, and ATX are equipped with longer ones. Due to their smaller size, SFX use quieter or smaller fans, while ATX use larger and more efficient coolers.

What types of cases support the SFX form factor?

The following ones:

• Mini-ITX. This is the most common option for small PCs that are designed for small PSUs form factors.
• Micro-ATX compact models. It’s perfect for these small cases that can’t accommodate an ATX power supply.
• HTPC / Small Form Factor (SFF) cases, for media centers or compact workstations.
• NCASE, DAN A4, and other premium SFF cases. Designed for high-performance, but small builds.

Are SFX power supplies suitable for Mini-ITX and Micro-ATX builds?

Sure, SFX small form factor PSUs perfectly go with Mini-ITX and compact Micro-ATX builds. They are compact for such cases and fully modular for more convenient and optimized cable management. Alongside this, they are capable of delivering sufficient power (300 W – 800 W and above) to support modern processors and graphics cards operations. In a nutshell, SFX allows you to build a powerful PC in a small case without any stability or cooling issues. They are small but no less powerful. 

How to use an SFX power supply in a mid-tower or full-tower case?

SFX PSUs are also compatible with mid-tower and full-tower cases. To install them correctly and use them for daily tasks – go for the short and simple step-by-step instructions. 

1. First, make sure you have special adapters and fixing frames to pin down the PSU inside the case. It’s a custom board that allows you to mount a compact SFX in a standard ATX slot.
2. Then, install the power supply in the standard ATX slot, securing it with the adapter.
3. Connect the necessary cables to it. SFX modular cables are usually long enough for mid/full-tower cases, but sometimes you will need to arrange them carefully.
4. Check the cooling. Make sure that the SFX fan is not blocked and that air can circulate freely inside the case.

What are the power and efficiency limitations of SFX power supplies?

SFX PSUs also come with certain limitations that are important to know before purchasing. Due to their compact internal layout, SFX power supplies can heat up and get louder under heavy loads. Their fans tend to spin faster than those in larger ATX units. 

SFX may not be sufficient for high-performance multi-card systems or professional PC builds. Because they typically deliver from 300W to 800W of power. Although top models can reach ~1000W. The latest SFX units are often 80 PLUS® Gold or Platinum certified. However, the smaller cooling chamber can restrict efficiency and raise temps under maximum load.

How do the cooling performances of SFX and ATX power supplies compare?

The cooling systems for ATX and SFX power supplies differ due to their sizes and construction design. 

• ATX PSU installed in a larger case for larger fans that rotate more slowly but cool the system more efficiently. Thus, it ensures a more stable and quieter cooling process, especially under high load.

• SFX PSU, in contrast, is installed in a compact case that limits the size of the fan. So, faster and smaller coolers are often used. Under full load, expect slightly higher temperatures and more audible fan noise. All in all, SFX is a compact solution that still delivers enough power for Mini-ITX or small Micro-ATX assemblies.

Which popular PC brands and models are compatible with SFX?

Here’s a roundup of the top brands that offer modern case models, compatible with SFX power supplies. 

• SilverStone. SG13, SG14 and Raven RVZ02/03 models. Compact SFF cases for high-performance Mini-ITX systems.
• Lian Li. TU150, A3-Mini, and Q58 models. Portable and elegant cases with SFX power supply support.
• Corsair. Crystal Series 280X cases for SFX PSUs (Mini-ITX).
• Fractal Design: Node 202, Era ITX. The company offers slim vertical cases, specifically for SFX power supplies.

For all these models, Seasonic SFX PSUs will perfectly meet their sizes to install them effortlessly.  

How to choose the right SFX power supply for the custom PC build?

Keep an eye on the following factors, and your choice will perfectly fit your expectations and PC needs. 

• Calculate how many watts your system needs. Add the processor, video card, storage devices, and peripherals’ power needs. Then add ~20-30% reserve. Just so you know, the Seasonic wattage calculator can do all the math for you and automatically consider extra power to add for the final figure. 
• Choose SFX PSU with the highest 80 PLUS® certification levels (Gold, Platinum, Titanium). It gives you less heat loss and a lower temperature inside the case.
• Make sure the case supports SFX or SFX-L formats; check the dimensions of the unit before purchasing.
• The unit should have a fully modular cable design to simplify its installation in a compact case. 

Conclusion

Despite its compact size, the SFX PSU still has many advantages over larger power supplies. It allows you to keep the aesthetic appearance of your system unit, doesn’t interfere with the installation of additional PC components, and supports maximum efficiency for all system parts.

Take into account its features and your PC characteristics to get the best result you need.

David Rigg

Hey, I’m David. I’ve been working as a wireless network engineer and a network administrator for 15 years. During my studies, I also worked as an ISP field technician – that’s when I met Jeremy. 

I hold a bachelor’s degree in network engineering and a master’s degree in computer science and engineering. I’m also a Cisco-certified service provider. 

In my professional career, I worked for router/modem manufacturers and internet providers. I like to think that I’m good at explaining network-related issues in simple terms. That’s exactly what I’m doing on this website – I’m making simple and easy-to-follow guides on how to install, set up, and troubleshoot your networking hardware. I also review new network equipment – modems, gateways, switches, routers, extenders, mesh systems, cables, etc. 

My goal is to help regular users with their everyday network issues, educate them, and make them less scared of their equipment. In my articles, you can find tips on what to look for when buying new networking hardware, and how to adjust your network settings to get the most out of your wi-fi. 

Since my work is closely related to computers, servers, and other network equipment, I like to spend most of my spare time outdoors. When I want to blow off some steam, I like to ride my bike. I also love hiking and swimming. When I need to calm down and clear my mind, my go-to activity is fishing.