What is the SFX form factor, and how is it different from ATX power supplies?
SFX it’s a Small Form Factor, a smaller version of a standard ATX computer PSU, designed for compact computer cases such as mini-ITX or microATX. It takes less space but operates as effectively as the bigger ones.
ATX measures 150 mm × 140 mm × 86 mm. SFX measures 100 mm × 125 mm × 63.5 mm, making it 30% smaller in volume. SFX is ideal for small form factor cases with limited space for additional components. ATX is used in larger systems with sufficient internal space.
SFX PSUs have shorter cables, which are ideal for compact cases. But at the same time, they may not be long enough for large cases. Modern SFX PSUs hit 850W and above, keeping up with ATX 3.0 and PCIe 5.0 standards.
Why do gamers and small form factor PC builders prefer SFX power supplies?
PC gamers and professionals choose SFX form factors due to their various advantages. First, they have compact sizes, which give the opportunity to add more components into a PC case but still get effective PSU operation during high-demanding games. Many SFX PC power supplies feature a fully modular design, allowing you to connect only the cables you need. This reduces clutter and improves airflow in small cases.
Also, modern SFX PSUs have 80 PLUS® Gold or Platinum certification, which ensures high energy efficiency and less heat emission. On top of that, compact dimensions make portable gaming systems convenient for LAN tournaments and mobile gaming.
How do SFX power supplies compare to ATX and TFX power supplies?
SFX, ATX, and TFX power supplies differ from each other by size, power capacity, and area of use.
ATX is a standard format for almost all PC building, in both mid and big case sizes. It provides high power and efficient cooling thanks to built-in large fans.
SFX – compact format for small cases, such as mini-ITX, allows powerful systems to be installed in a small space. It goes with modular cables and 80 PLUS® Gold or Platinum certification.
TFX – a slim PSU format for narrow cases, such as HTPCs, with lower power (200–500 W), suitable for low-power or budget systems.
What are the main advantages of SFX power supplies compared to other compact PSUs?
The first thing is its effective combination of size, power, and productivity. Despite its small dimensions, this PSU delivers as much power as your PC needs to handle game sessions, stable operation in long working hours, and other demanding tasks.
Their size allows them to be installed in small mini-ITX cases. At the same time, modern models can deliver up to 850 W, supporting powerful components such as modern graphics cards.
How do the leading manufacturers (Seasonic, Corsair, SilverStone) compete in the SFX power supply market?
Seasonic is known as a leader in manufacturing reliable and high-productive PSUs that provide stable operation, low noise level, and come with up to a 12-year warranty. All these make it the choice number one for those PC enthusiasts who value reliability and stable PSU performance over time.
Corsair offers compact SF PSUs models that support modern standards such as PCIe 5.0, with efficiency and a convenient modular design. The warranty is usually shorter, up to 7 years.
SilverStone stands out for its ability to deliver high power in an SFX-L form factor, which is suitable for small gaming systems and compact PC enthusiasts.
Are there any trade-offs between size, cooling, and noise levels between SFX power supplies and other types?
SFX power supplies have a compact size, which makes them convenient to use in small mini-ITX and HTPC cases. However, due to their smaller fans, they are less efficient at cooling. As a result, they may be noisier than larger ATX units. But still, thanks to their compact size, they produce minimal noise and rarely disturb users at work. ATX PSU models, on the other hand, have large fans. It allows them to provide better heat dissipation and quieter operation under high loads.
How do SFX power supply prices compare to similar options from other brands?
Prices for SFX power supplies vary depending on the brand, efficiency certification, and additional features. SFX power supplies are typically more expensive than comparable ATX models. It’s cuz of their compact size, specialized design, and use of high-quality components. For example, the Corsair SF850 (2024) costs around $224.99. ATX units with the same power output can be found for as low as $99.99.
Which form factor is best for your next PC build?
The form factor you choose for your PC depends on the size you need, system power capacity, and cooling options. Estimate your requirements first and then choose from the form factors the market offers.
ATX in most cases goes better with standard gaming and work PCs, as it provides high power and effective cooling thanks to large fans. SFX and SFX-L are the optimal choice for compact mini-ITX cases, providing good power in a small space, although they can be noisier due to smaller fans.
Note the golden rule – the power supply must be compatible with the case and meet your power and cooling requirements first.
Conclusion
As you can see, SFX form factor PSUs have lots of advantages and are actively used by professional PC builders for various tasks. It’s up to you what PSU to choose, but always dig deeper to see the whole picture of what different form factors offer and what your PC actually needs and supports.
