solderic.com ATX power supplies offer higher wattage and larger sizes suitable for full-sized desktop builds, while SFX power supplies provide compact form factors ideal for small or mini-ITX systems without sacrificing significant power output. Discover which power supply best matches Your PC build needs by reading the full comparison.
Comparison Table
| Feature | ATX Power Supply | SFX Power Supply |
|---|---|---|
| Size | Standard full-size (150mm x 140mm x 86mm) | Compact small form factor (125mm x 100mm x 63.5mm) |
| Power Output | Typically 300W to 1200W+ | Typically 300W to 700W |
| Compatibility | Designed for mid-tower and full-tower ATX cases | Designed for small form factor (SFF) cases, mini-ITX builds |
| Cooling | Larger fan, quieter operation | Smaller fan, may be louder under load |
| Connector Types | Standard ATX connectors (24-pin, 8-pin CPU, PCIe) | Same connectors but often shorter cables |
| Use Cases | Gaming PCs, workstations, high-power systems | Compact PCs, HTPCs, portable and space-limited builds |
| Price | Generally more affordable and widely available | Typically higher cost per watt due to compact design |
Overview of ATX and SFX Power Supplies
ATX power supplies typically offer higher wattage options ranging from 300W to 1200W and larger form factors designed for standard desktop cases, providing extensive compatibility with motherboards and multiple GPU setups. SFX power supplies are more compact at 65mm x 125mm x 100mm, delivering wattages mainly between 300W and 600W, optimized for small form factor (SFF) builds prioritizing space efficiency without sacrificing power delivery. Both ATX and SFX units incorporate similar features like modular cabling and 80 Plus efficiency ratings, but the choice depends on case size constraints and power requirements.
Physical Size and Form Factor Comparison
ATX power supplies are generally larger, measuring around 150mm x 140mm x 86mm, making them suitable for mid-tower and full-tower PC cases. SFX power supplies, typically sized at 125mm x 100mm x 63.5mm, offer a compact form factor ideal for small form factor (SFF) builds without compromising power output. Your choice between ATX and SFX should consider the internal space of your case and airflow requirements for optimal system performance.
Wattage and Power Output Differences
ATX power supplies typically offer wattages ranging from 300W to 1200W, making them suitable for high-performance gaming rigs and workstations requiring substantial power output. SFX power supplies usually provide lower wattages between 300W and 700W, designed for compact builds with limited space and moderate power demands. The wattage difference directly impacts compatibility, with ATX units supporting more power-hungry components, while SFX units prioritize efficiency and size constraints over maximum power output.
Compatibility with PC Cases
ATX power supplies are compatible with standard mid-tower and full-tower PC cases, offering broad support for mainstream builds due to their larger size and wattage capacity. SFX power supplies are designed for small form factor (SFF) cases, providing high power output in a compact size that fits mini-ITX or micro-ATX cases with limited space. Ensuring the power supply matches the case form factor is critical for proper installation, optimal airflow, and overall system stability.
Modular vs Non-Modular Options
ATX power supplies typically offer a wide range of modular, semi-modular, and non-modular options, allowing you to choose based on cable management preferences and system build complexity. SFX power supplies, while compact and ideal for small form factor builds, primarily offer modular designs to maximize airflow and reduce clutter in limited space. Choosing between modular and non-modular in either form factor depends on your need for customization and ease of installation.
Efficiency and Certification Ratings
ATX power supplies often come with a wide range of efficiency certifications, including 80 Plus Bronze, Silver, Gold, Platinum, and Titanium, ensuring reliable energy use and reduced heat output. SFX power supplies, while smaller in size, also offer these certifications but may have fewer high-wattage options, impacting maximum efficiency at higher loads. Your choice between ATX and SFX should consider certification ratings like 80 Plus Gold or higher to guarantee optimal power efficiency for your system's needs.
Noise Levels and Cooling Solutions
ATX power supplies typically feature larger fans, often 120mm or more, providing efficient cooling at lower noise levels due to slower fan speeds. SFX power supplies, designed for compact systems, use smaller fans around 80mm to 92mm, which may run at higher RPMs resulting in increased noise under heavy loads. Advanced models in both categories incorporate semi-fanless or hybrid cooling technologies to optimize airflow while minimizing acoustic impact.
Cable Management Capabilities
ATX power supplies generally offer more extensive cable management options with numerous connectors and longer cables suited for larger PC cases and complex builds. SFX power supplies, designed for compact systems, provide limited cable length and fewer connectors, which can simplify cable routing but constrain flexibility in cabling configurations. Effective cable management in ATX units enhances airflow and aesthetics, while SFX units prioritize space efficiency with shorter cable runs and modular designs tailored for small form factors.
Pricing and Value Considerations
ATX power supplies generally offer a broader range of wattages and features at more competitive prices due to their widespread use and larger market availability. SFX power supplies, being smaller and designed for compact builds, tend to carry a price premium, reflecting their specialized form factor and engineering. Consumers seeking cost-effective solutions for standard builds often favor ATX units, while those prioritizing space-saving designs may accept the higher investment in SFX models for optimized value in compact setups.
Choosing the Right PSU for Your Build
Selecting the right PSU for your build depends on form factor, power output, and efficiency. ATX power supplies offer higher wattage options and extensive connector choices suitable for standard or high-performance systems. SFX power supplies provide compact size ideal for small form factor builds, ensuring optimal power delivery without sacrificing space.
atx power supply vs sfx power supply Infographic
