Best SFX PC Power Supplies: 15 Spec-Based Picks
As an Amazon Associate we earn from qualifying purchases. Links on this page are affiliate links.
Finding the right SFX PC power supply is essential when assembling a compact computer build. We compared 15 products based on the specifications published on the listings. The SilverStone 700W SFX 80 Plus Gold Power Supply leads the list because it provides 700 watts of output and 80 Plus Gold efficiency in a fully modular housing.
This guide helps you decide which unit delivers the appropriate wattage, cabling modularity, and physical dimensions for your specific small-form-factor case.
Quick picks
The best fit for you
- You build a standard 700W small-form-factor PC SilverStone 700W SFX 80 Plus Gold Power Supply It provides 700W continuous output, 80 Plus Gold efficiency, and fully modular flat cables.
- You run a low-draw system requiring continuous power SilverStone 300W SFX Bronze Power Supply This unit delivers 300W continuous output and includes an ATX mounting bracket.
- You power a modern GPU needing PCIe 5.1 support Cooler Master V750 SFX Gold PCIe 5.1 PSU It features PCIe 5.1 compatibility with right-angle cabling delivering up to 450W to your GPU.
- You need maximum wattage backed by a long warranty EVGA SuperNOVA 850 GM SFX Power Supply It supplies 850W output, 80 Plus Gold efficiency, and a 10-year warranty.
Our 15 picks
SilverStone 700W SFX 80 Plus Gold Power Supply
Best for: 700W small-form-factor PC builds
- Form Factor
- SFX (what this guide is about)
- Wattage
- 700W
- Efficiency Rating
- 80 PLUS Gold
- Modularity
- Fully Modular
- Fan Size
- 92mm
- Dimensions
- 4.92 × 3.94 × 2.5 inches
View on Amazon: SilverStone 700W SFX 80 Plus Gold Power Supply
The SilverStone 700W Gold Fully Modular SFX PSU delivers 700W of power with 80 PLUS Gold efficiency in a compact SFX footprint. It features fully modular flexible flat cables, all Japanese capacitors, and tight 3% voltage regulation on a single +12V rail. A 92mm fluid dynamic bearing fan provides cooling at 18 dBA minimum. It suits you if you want high-efficiency modular power for tight mini-ITX cases.
Pros
- 80 PLUS Gold certified energy efficiency
- 100% modular design with flexible flat cables
- All Japanese capacitors
- Single +12V rail with 3% voltage regulation
- 92mm FDB fan rated at 18 dBA minimum
Cons
- Not compatible with standard ATX power supply mounting holes
- Fan operates at 18 dBA minimum with no passive zero-RPM mode listed
Good fit if
- You need 700W of power for a dedicated SFX mounting location.
- You want fully modular flat cabling to ease routing in small enclosures.
- You prefer all Japanese capacitors for power delivery.
Skip if
- You need to mount the power supply into an ATX bracket location.
- You require more than 700W of total capacity for your hardware.
Verdict: SilverStone 700W Gold Fully Modular SFX PSU delivers stable 700W output and 80 PLUS Gold efficiency within standard SFX dimensions. Its fully modular flat cabling and Japanese capacitors make it a solid foundation for compact systems.
SilverStone 450W SFX Bronze Power Supply
Best for: modest wattage small form factor systems
- Form Factor
- SFX (what this guide is about)
- Wattage
- 450W
- Efficiency Rating
- 80 Plus Bronze
- Dimensions
- 9 × 7 × 4 inches
The SilverStone 450W Bronze SFX Power Supply provides 450W of continuous power for compact builds. It features 80 Plus Bronze efficiency, reaching 82% to 85% efficiency under typical loads. A dedicated single +12V rail supplies 36A, and an included adapter bracket allows installation in standard ATX cases. You will find this power supply fits low-power small form factor computers that do not require high wattage.
Pros
- Delivers 450W continuous output rated for 24/7 operation
- Single +12V rail provides up to 36A
- Includes an adapter bracket to fit ATX cases
- 80 Plus Bronze certified for 82% to 85% efficiency
Cons
- 450W total output limits higher-draw hardware
- Bronze efficiency rates lower than Gold or Platinum alternatives
Good fit if
- You build a lower-power system requiring 450W or less.
- You need an SFX supply that includes an ATX mounting bracket.
Skip if
- You need more than 450W of continuous power.
- You target 80 Plus Gold or higher electrical efficiency.
Verdict: SilverStone 450W Bronze SFX Power Supply delivers dependable continuous power for modest small form factor systems that need 450W or less.
SilverStone 700W Platinum SFX-L Power Supply
Best for: quiet compact builds needing Platinum efficiency
- Form Factor
- SFX (what this guide is about)
- Wattage
- 700W
- Efficiency Rating
- 80 PLUS Platinum
- Modularity
- Fully Modular
- PCIe Connector Type
- PCI-E 8/6pin
- Fan Size
- 120mm
View on Amazon: SilverStone 700W Platinum SFX-L Power Supply
This SilverStone unit provides 700 watts of continuous power in a compact form factor equipped with a full 120mm cooling fan. Rated for 80 PLUS Platinum efficiency and 24/7 operation, it features fully modular flat flexible cables alongside semi-fanless fan control. It suits you if you build a compact PC where low acoustic output and high electrical efficiency matter, provided your enclosure accommodates its 5.12-inch length.
Pros
- 80 PLUS Platinum efficiency rating
- 120mm fan with semi-fanless operation
- 700W continuous output rated for 24/7 operation
- Fully modular flat flexible cables
- Supports quad PCI-E 8/6-pin connectors
Cons
- Length of 5.12 inches requires more chassis space than standard SFX
- Output limited to 700W continuous
Good fit if
- You need 80 PLUS Platinum efficiency with a 120mm cooling fan.
- You want fully modular flexible flat cables with quad PCI-E connectors.
- You require 700W continuous output rated for 24/7 operation.
Skip if
- You need more than 700W of total power.
- You have a tight chassis unable to fit a 5.12-inch long power supply.
Verdict: SilverStone 700W Platinum 120mm Fan SFX Power Supply delivers 80 PLUS Platinum efficiency and 24/7 continuous output in a compact chassis with a 120mm fan. It is a solid choice for small form factor builds with space for a 5.12-inch depth.
SilverStone 300W SFX Bronze Power Supply
Best for: low-draw systems needing continuous 24/7 power
- Form Factor
- SFX (what this guide is about)
- Wattage
- 300W
- Efficiency Rating
- 80 Plus Bronze
- Fan Size
- 92mm
- Dimensions
- 3.94 × 4.92 × 2.5 inches
The SilverStone 300W Bronze SFX Power Supply is a compact unit designed for low-power small form factor systems. It delivers 300W of continuous power at 40℃ with 80 Plus Bronze efficiency between 82% and 85%. It features a 92mm silent cooling fan, a single +12V rail, and an included ATX adapter bracket. You get continuous power output engineered for 24/7 operation in smaller enclosures.
Pros
- 300W continuous power output rated for 24/7 operation at 40℃
- 80 Plus Bronze efficiency rating reaching up to 85%
- Includes bracket to support standard ATX mounting
- Equipped with a silent running 92mm cooling fan
Cons
- 300W output limits compatibility with high-power hardware
- 80 Plus Bronze efficiency is lower than Gold or Platinum models
Good fit if
- You need an SFX power supply rated for continuous 24/7 operation at 40℃.
- You want an included adapter bracket to mount an SFX unit in an ATX case.
Skip if
- You need more than 300W of continuous output for demanding components.
- You require 80 Plus Gold or higher efficiency ratings.
Verdict: SilverStone 300W Bronze SFX Power Supply provides 300W continuous output and an included ATX mounting bracket. It offers a practical solution for low-power builds requiring 24/7 operation.
SilverStone 700W Platinum SFX Power Supply
Best for: high-efficiency compact PC builds
- Form Factor
- SFX (what this guide is about)
- Wattage
- 700W
- Efficiency Rating
- 80 PLUS Platinum
- Fan Size
- 92mm
- Dimensions
- 3.94 × 4.92 × 2.5 inches
- Weight
- 4.59 pounds
The SilverStone 700W Platinum SFX Power Supply is a compact unit designed for small-form-factor builds. It delivers 700 watts of power with an 80 Plus Platinum efficiency rating to help limit waste heat in tight cases. Inside, it uses all Japanese capacitors and a 92mm fluid dynamic bearing fan rated down to 18 dBA. This unit suits you if you need high electrical efficiency in a standard SFX footprint.
Pros
- 80 Plus Platinum efficiency rating
- All Japanese capacitors
- 92mm FDB fan with 18 dBA minimum noise level
- Standard SFX dimensions (4.92 x 2.5 x 3.94 inches)
Cons
- ATX mounting adapter is sold separately
- 700W capacity is lower than 750W or 850W options
Good fit if
- You need 80 Plus Platinum efficiency in an SFX enclosure.
- You want an internal 92mm fan rated at 18 dBA minimum.
- You are building a system that requires up to 700 watts of power.
Skip if
- You need an included ATX mounting bracket.
- You require more than 700 watts for higher-draw hardware.
Verdict: SilverStone 700W Platinum SFX Power Supply provides 80 Plus Platinum efficiency and all Japanese capacitors within a standard SFX footprint. It is a solid match for compact builds needing reliable 700-watt power delivery.
Cooler Master V750 SFX Gold PCIe 5.1 PSU
Best for: Mini-ITX builds needing PCIe 5.1 GPU power
- Form Factor
- SFX (what this guide is about)
- Efficiency Rating
- Gold
- ATX Version
- ATX 3.1
- PCIe Connector Type
- 12VHPWR
- PCIe Version
- PCIe 5.1
- Dimensions
- 3.94 × 4.92 × 2.5 inches
The Cooler Master V750 SFX Gold is a 750W power supply designed for compact Mini-ITX systems. It delivers dedicated GPU power using an ATX 3.1 cable with a 90-degree 12VHPWR connector rated for up to 450W. Its 4.92 by 3.94 by 2.5-inch chassis fits small enclosures directly. This unit suits you if you need modern PCIe 5.1 graphics card connectivity while managing tight internal case clearances.
Pros
- Features a 90° 12VHPWR PCIe 5.1 connector
- ATX 3.1 cable delivers up to 450W to the GPU
- Compact SFX housing measuring 4.92 by 3.94 by 2.5 inches
- Custom short cables minimize interior case clutter
Cons
- PCIe 5.1 power delivery capped at 450W
- Included short cables may require extensions for larger enclosures
Good fit if
- You build in a Mini-ITX chassis needing angled 12VHPWR cable clearance.
- You run a modern graphics card drawing up to 450W.
Skip if
- You need more than 450W over a single 12VHPWR connection.
- You install the unit in a larger case requiring standard-length cables.
Verdict: Cooler Master V750 SFX Gold PCIe 5.1 PSU provides 750W of power in an SFX footprint with right-angle ATX 3.1 cabling. It is a precise fit for compact builds requiring up to 450W GPU delivery.
SilverStone SX750 750W SFX Platinum PSU
Best for: compact builds needing high Platinum efficiency
- Form Factor
- SFX (what this guide is about)
- Wattage
- 750W
- Efficiency Rating
- 80 PLUS Platinum
- Modularity
- Fully Modular
- Fan Size
- 92mm
- Dimensions
- 10 × 8 × 4 inches
This SilverStone unit delivers 750 watts of power in a standard SFX form factor. It features 80 PLUS Platinum efficiency and completely modular, flexible flat cables. A 92mm dual ball bearing fan provides cooling with automatic start-stop operation tied to load and temperature. All internal capacitors are Japanese. You will find it well suited for compact, high-efficiency small form factor builds requiring reliable, regulated power delivery.
Pros
- 80 PLUS Platinum efficiency certification
- Fully modular design with flexible flat cables
- All Japanese capacitors
- 92mm dual ball bearing fan with auto start-stop
- Strict ±3% voltage regulation
Cons
- 750-watt ceiling limits high-draw hardware configurations
- No native PCIe 5.0 cables listed in the specifications
Good fit if
- You want 80 PLUS Platinum efficiency in a standard SFX case.
- You need flexible flat modular cables for simpler routing in tight spaces.
- You prefer a semi-passive cooling fan that stops during low loads.
Skip if
- You require more than 750 watts for your system components.
- You need a power supply with listed PCIe 5.0 connectors.
Verdict: SilverStone 750W Platinum SFX Power Supply delivers clean power with tight voltage regulation in compact enclosures. It combines 80 PLUS Platinum efficiency with fully modular flat cabling and semi-passive cooling.
EVGA SuperNOVA 850 GM SFX Power Supply
Best for: high-power small-form-factor builds needing 850W
- Form Factor
- SFX (what this guide is about)
- Wattage
- 850W
- Efficiency Rating
- 80 PLUS Gold
- Modularity
- Fully Modular
- Warranty
- 10 Year
- Dimensions
- 4.92 × 4.92 × 2.48 inches
The EVGA SuperNOVA GM 850W SFX Power Supply delivers 850 watts of output in a compact 4.92-inch SFX chassis. You get an 80 Plus Gold efficiency rating, fully modular cabling, and 100% Japanese capacitors. An included ATX adapter bracket lets you install it in standard desktop cases as well as mini-ITX enclosures. It suits you if you build a high-draw compact system and need reliable power with a 10-year warranty.
Pros
- 850W capacity in a compact SFX form factor
- 80 Plus Gold efficiency rating
- Fully modular cable configuration
- Includes ATX mounting bracket
- 10-year manufacturer warranty
Cons
- 80 Plus Gold rating rather than Platinum efficiency
- Weighs 4 pounds
Good fit if
- You need 850W of power for a demanding small-form-factor PC build.
- You want fully modular cabling to minimize clutter in tight spaces.
- You plan to mount an SFX unit into an ATX case using the included bracket.
Skip if
- You require 80 Plus Platinum efficiency for your setup.
- You only require a lower wattage unit such as 450W or 550W.
Verdict: EVGA SuperNOVA GM 850W SFX Power Supply pairs high 850W output with 80 Plus Gold efficiency and a 10-year warranty. It provides substantial power and modular cable routing for compact, performance-focused builds.
SilverStone 750W Platinum SFX PSU
Best for: high-efficiency small form factor PC builds
- Form Factor
- SFX (what this guide is about)
- Wattage
- 750W
- Efficiency Rating
- 80 Plus Platinum
- Modularity
- Fully Modular
- Fan Size
- 92mm
- Dimensions
- 3.94 × 4.92 × 2.5 inches
This unit is a 750W SFX power supply designed for compact computer builds. You get an 80 PLUS Platinum efficiency rating, fully modular cabling, and all-Japanese capacitors inside standard SFX dimensions of 4.92 by 3.94 by 2.5 inches. Its 92mm dual ball bearing fan includes an auto start-stop function that responds to load and temperature. It suits you if you need high efficiency and clean cable management in a small form factor case.
Pros
- 80 PLUS Platinum efficiency rating
- Fully modular cable design
- All-Japanese internal capacitors
- 92mm dual ball bearing fan with auto start-stop
Cons
- 92mm fan is smaller than 120mm options on SFX-L units
- 750W output limits support for high-draw hardware configurations
Good fit if
- You need 80 PLUS Platinum efficiency in a standard SFX footprint.
- You want fully modular cables to minimize clutter inside a small case.
- You prefer a semi-passive fan mode for silent operation at low loads.
Skip if
- You need more than 750W of power for top-tier components.
- You prefer the larger 120mm fan found on SFX-L form factors.
Verdict: SilverStone 750W Platinum SFX Power Supply provides high electrical efficiency and fully modular cabling in a strict SFX envelope. It delivers reliable power and zero-RPM cooling for compact enclosures.
Lian Li 750W SFX Gold Power Supply
Best for: clean, low-noise compact SFX PC builds
- Form Factor
- SFX (what this guide is about)
- Wattage
- 750W
- Efficiency Rating
- 80 PLUS GOLD
- Modularity
- Fully modular
- Dimensions
- 9.5 × 4.13 × 7 inches
- Weight
- 2.2 pounds
This Lian Li unit provides 750 watts of output in a standard SFX form factor. It carries an 80 PLUS Gold efficiency rating and features Japanese electrolytic capacitors. You get fully modular braided cables and a zero-RPM fan mode that stays silent under 40 percent load. It suits your compact small-form-factor build when you need dependable power delivery without extra cable clutter inside a crowded case.
Pros
- 80 PLUS Gold efficiency rating
- Zero-RPM fan mode below 40% load
- Fully modular braided cables
- Japanese electrolytic capacitors
Cons
- Zero-RPM silent mode disengages above 40% load
- Gold efficiency rating rather than Platinum
Good fit if
- You need 750W of power in an SFX enclosure.
- You want silent fan-stop operation during light computing tasks under 40% load.
- You want flexible braided cables to simplify routing in tight spaces.
Skip if
- You require an 80 PLUS Platinum efficiency rating.
- You need higher capacity than 750 watts for demanding components.
Verdict: Lian Li 750W SFX Gold Power Supply delivers clean modular power with silent operation under light loads. Its 80 PLUS Gold efficiency and Japanese capacitors make it dependable for compact builds.
Lian Li 750W SFX Gold Power Supply
Best for: compact builds needing 750W Gold modular power
- Form Factor
- SFX (what this guide is about)
- Wattage
- 750W
- Efficiency Rating
- 80 PLUS Gold
- Modularity
- Fully Modular
- Dimensions
- 4 × 3 × 5 inches
This Lian Li unit provides 750 watts of continuous power inside a compact SFX form factor. It carries an 80 Plus Gold efficiency certification to reduce wasted heat during typical system loads. The fully modular design lets you attach only the cables required for your build, saving space in tight enclosures. It suits your compact desktop setup when you need dedicated power in a standard black finish.
Pros
- 750-watt power delivery
- 80 Plus Gold efficiency rating
- Fully modular cable design
- Compact SFX form factor
Cons
- Efficiency rated at 80 Plus Gold rather than Platinum
- Only listed in a black color finish
Good fit if
- You need a 750W power supply designed for an SFX chassis.
- You want fully modular cables to simplify cable routing in small cases.
- You require 80 Plus Gold certified electrical efficiency.
Skip if
- You need more than 750 watts for high-draw hardware configurations.
- You require an 80 Plus Platinum or Titanium efficiency tier.
- You are building a white-themed system.
Verdict: Lian Li 750W Gold SFX Power Supply provides high wattage and fully modular routing for space-constrained cases. It gives your small-form-factor build certified Gold efficiency without unnecessary fixed cabling.
SilverStone 750W Gold SFX Power Supply
Best for: compact small-form-factor builds needing 750W
- Form Factor
- SFX (what this guide is about)
- Wattage
- 750W
- Efficiency Rating
- 80 Plus Gold
- Modularity
- Fully Modular
- Fan Size
- 92mm
- Dimensions
- 3.94 × 4.92 × 2.5 inches
This SilverStone unit supplies 750W of power within a standard SFX form factor. It features 80 Plus Gold efficiency, a single +12V rail, and all Japanese electrolytic capacitors with strict ±3% voltage regulation. You get fully modular flat cables with 180° angled SATA connectors alongside a 92mm HYB cooling fan. This makes it a clean match if you assemble a tight small-form-factor system.
Pros
- 80 Plus Gold efficiency certification
- All Japanese electrolytic capacitors on a single +12V rail
- Strict ±3% voltage regulation with low ripple and noise
- Fully modular flat cables with 180° angled SATA connectors
- Silent 92mm HYB cooling fan
Cons
- Rated 80 Plus Gold rather than Platinum efficiency
- Zero-RPM fan mode not listed in specifications
Good fit if
- You need a standard SFX 750W supply with fully modular flat cabling.
- You want Japanese capacitors and ±3% voltage regulation.
- You use stacked drive mounts requiring 180° angled SATA connectors.
Skip if
- You require higher 80 Plus Platinum efficiency.
- You prefer a larger 120mm fan design.
Verdict: SilverStone 750W Gold Fully Modular SFX PSU provides strict ±3% voltage regulation, all Japanese capacitors, and flat modular cabling in a standard SFX footprint. It offers balanced 750W Gold efficiency for compact chassis builds.
Lian Li SP 750W Gold SFX Power Supply
Best for: compact desktop builds needing 750W efficiency
- Form Factor
- SFX (what this guide is about)
- Wattage
- 750 WATT
- Efficiency Rating
- 80 Plus Gold
- Modularity
- Fully Modular
- Dimensions
- 10 × 8 × 5 inches
This Lian Li unit provides 750 watts of output in a compact SFX form factor. It carries an 80 Plus Gold efficiency certification to keep power loss down during everyday operation. The fully modular design lets you attach only the cables your compact PC build requires. It suits you if you need a clean small-form-factor setup with steady wattage.
Pros
- 750-watt power capacity
- 80 Plus Gold efficiency rating
- Fully modular cable configuration
- Compact SFX form factor
Cons
- No PCIe 5.0 or 12VHPWR cable listed in specifications
- No semi-passive or zero-RPM fan mode documented
Good fit if
- You need a 750-watt power supply for a compact SFX-compatible enclosure.
- You want fully modular cables to reduce clutter inside a small chassis.
- You target an 80 Plus Gold efficiency level for everyday power management.
Skip if
- You require 850 watts or more for higher-draw components.
- You need native PCIe 5.0 12VHPWR power connectivity out of the box.
Verdict: Lian Li SP 750W Gold SFX Power Supply delivers 750 watts and fully modular cabling in a standard SFX footprint. It provides an efficient 80 Plus Gold baseline for compact desktop builds.
Lian Li 850W White SFX Power Supply
Best for: white small-form-factor builds needing 850W capacity
- Form Factor
- SFX (what this guide is about)
- Wattage
- 850 WATT
- Efficiency Rating
- 80 Plus Gold
- Modularity
- Fully Modular
This Lian Li unit is an 850W SFX power supply built for compact desktop systems. It delivers an 80 Plus Gold efficiency rating and features a fully modular cable configuration to minimize internal clutter. The white exterior matches coordinated light-colored builds. If you need high wattage and clean cable management inside a space-constrained small-form-factor enclosure, this power supply provides the required capacity and modular flexibility for your hardware setup.
Pros
- 850W power output
- 80 Plus Gold efficiency rating
- Fully modular cabling design
- Compact SFX form factor
- White finish for themed setups
Cons
- Efficiency is 80 Plus Gold rather than Platinum
- Color is limited to white in these specifications
Good fit if
- You need an 850W power supply in the compact SFX form factor.
- You want a fully modular power supply with a white exterior finish.
- You require 80 Plus Gold energy efficiency for your small build.
Skip if
- You prefer a standard black finish for your components.
- You need higher efficiency than the 80 Plus Gold tier.
Verdict: Lian Li 850W White SFX Power Supply delivers 850 watts of 80 Plus Gold power in a fully modular compact frame. It suits builders who need high wattage and a clean white aesthetic for small-form-factor enclosures.
Lian Li SP850 850W Gold SFX Power Supply
Best for: high-wattage small-form-factor PC builds
- Form Factor
- SFX (what this guide is about)
- Wattage
- 850W
- Efficiency Rating
- 80+ Gold
- Modularity
- Fully Modular
- Dimensions
- 10 × 8 × 5 inches
The Lian Li SP850 delivers 850 watts of power inside a compact SFX form factor. It features 80 Plus Gold efficiency and a fully modular design, allowing you to connect only the cables you need. The unit includes 16 AWG wiring to support demanding hardware setups. This makes it a dependable fit if you are assembling a high-draw, small-form-factor PC build that requires clean cable management.
Pros
- 850W power output in an SFX enclosure
- 80 Plus Gold certified efficiency
- Fully modular cable system
- Includes 16 AWG wire gauge cabling
Cons
- Efficiency limited to 80 Plus Gold rather than Platinum
- Cooling fan noise and zero-RPM data not listed in specifications
Good fit if
- You need 850W of capacity for a compact SFX build.
- You want fully modular cabling with 16 AWG wire gauge.
- You target 80 Plus Gold power efficiency.
Skip if
- You require an 80 Plus Platinum or Titanium rating.
- You need documented fan noise specifications before purchasing.
Verdict: Lian Li SP850 850W Gold SFX Power Supply delivers 850W of power and 80 Plus Gold efficiency in a fully modular SFX chassis. It provides heavy-gauge 16 AWG wiring for dense, high-demand small-form-factor systems.
Specifications side by side
| Spec | SilverStone 700W SFX 80 Plus Gold Power Supply | SilverStone 450W SFX Bronze Power Supply | SilverStone 700W Platinum SFX-L Power Supply | SilverStone 300W SFX Bronze Power Supply | SilverStone 700W Platinum SFX Power Supply | Cooler Master V750 SFX Gold PCIe 5.1 PSU | SilverStone SX750 750W SFX Platinum PSU | EVGA SuperNOVA 850 GM SFX Power Supply | SilverStone 750W Platinum SFX PSU | Lian Li 750W SFX Gold Power Supply | Lian Li 750W SFX Gold Power Supply | SilverStone 750W Gold SFX Power Supply | Lian Li SP 750W Gold SFX Power Supply | Lian Li 850W White SFX Power Supply | Lian Li SP850 850W Gold SFX Power Supply |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Wattage | 700W | 450W | 700W | 300W | 700W | not specified | 750W | 850W | 750W | 750W | 750W | 750W | 750 WATT | 850 WATT | 850W |
| Efficiency Rating | 80 PLUS Gold | 80 Plus Bronze | 80 PLUS Platinum | 80 Plus Bronze | 80 PLUS Platinum | Gold | 80 PLUS Platinum | 80 PLUS Gold | 80 Plus Platinum | 80 PLUS GOLD | 80 PLUS Gold | 80 Plus Gold | 80 Plus Gold | 80 Plus Gold | 80+ Gold |
| Modularity | Fully Modular | not specified | Fully Modular | not specified | not specified | not specified | Fully Modular | Fully Modular | Fully Modular | Fully modular | Fully Modular | Fully Modular | Fully Modular | Fully Modular | Fully Modular |
| ATX Version | not specified | not specified | not specified | not specified | not specified | ATX 3.1 | not specified | not specified | not specified | not specified | not specified | not specified | not specified | not specified | not specified |
| PCIe Connector Type | not specified | not specified | PCI-E 8/6pin | not specified | not specified | 12VHPWR | not specified | not specified | not specified | not specified | not specified | not specified | not specified | not specified | not specified |
| Fan Size | 92mm | not specified | 120mm | 92mm | 92mm | not specified | 92mm | not specified | 92mm | not specified | not specified | 92mm | not specified | not specified | not specified |
| Warranty | not specified | not specified | not specified | not specified | not specified | not specified | not specified | 10 Year | not specified | not specified | not specified | not specified | not specified | not specified | not specified |
| Form Factor | SFX | SFX | SFX | SFX | SFX | SFX | SFX | SFX | SFX | SFX | SFX | SFX | SFX | SFX | SFX |
| PCIe Version | not specified | not specified | not specified | not specified | not specified | PCIe 5.1 | not specified | not specified | not specified | not specified | not specified | not specified | not specified | not specified | not specified |
| Size | 700W | 450W | 700W SFX12V | 300W V2 | 700W | 750 | not specified | 850W | 750W | 750W(V1),Black | not specified | 750W | not specified | not specified | 16 AWG size |
| Dimensions | 4.92 × 3.94 × 2.5 inches | 9 × 7 × 4 inches | 5.12 × 4.92 × 2.5 inches | 3.94 × 4.92 × 2.5 inches | 3.94 × 4.92 × 2.5 inches | 3.94 × 4.92 × 2.5 inches | 10 × 8 × 4 inches | 4.92 × 4.92 × 2.48 inches | 3.94 × 4.92 × 2.5 inches | 9.5 × 4.13 × 7 inches | 4 × 3 × 5 inches | 3.94 × 4.92 × 2.5 inches | 10 × 8 × 5 inches | not specified | 10 × 8 × 5 inches |
| Weight | 3.09 pounds | not specified | 5.07 pounds | not specified | 4.59 pounds | 3.13 pounds | 4.47 pounds | 4 pounds | not specified | 2.2 pounds | not specified | 4.45 pounds | not specified | not specified | not specified |
| Color | Black?Lead-Free Paint? | not specified | not specified | not specified | not specified | Black Edition | not specified | not specified | not specified | Black | Black | not specified | Black | white | not specified |
| Model | SST-SX700-G | SST-ST45SF-V3-USA | SST-SX700-LPT | SST-ST30SF V2 | SX700-PT | MPY-7501-SFHAGV-3U1 | SX750-PT | 123-GM-0850-X1 | PS-SX750-PT-X | SP750 | SP750 | not specified | SP750 WHITE | SP850W | SP850B |
Is an SFX Power Supply Worth It?
SFX units deliver full desktop power in compact footprints measuring roughly 3.94 inches deep and 2.5 inches high. Choosing SFX frees volume inside space-constrained chassis for airflow, discrete graphics cards, and component access. Listed units deliver 300W to 850W with 80 PLUS Bronze, Gold, or Platinum efficiency. Models feature Japanese capacitors, semi-passive zero-RPM fan modes for silent operation during light loads, and fully modular cables. This form factor gives small systems continuous high-wattage power without occupying standard ATX space.
Worth it if
- You assemble a compact Mini-ITX build that cannot physically house a standard ATX power supply.
- You require high output up to 850W and 80 PLUS Platinum or Gold efficiency in a small enclosure.
- You need semi-passive zero-RPM cooling for silent fan operation at low loads.
Skip it if
- You build inside a standard ATX chassis that accommodates full-sized power supplies.
- You require long native power cables designed specifically for large tower enclosures.
If you plan to install liquid cooling, you can evaluate clearance specifications across the best PC cases for radiator to ensure proper fitment.
How We Picked SFX PSUs
You see 15 power supplies selected strictly for the SFX form factor. We identify each unit when published Amazon listings state the SFX form factor in the title or feature list. All details come directly from published specifications. We do not physically handle the hardware.
Only one size or variant of each product family appears on the list. Products in stock display first to help you find available hardware immediately. This format lets you compare published wattage, efficiency ratings, and modularity directly from technical specs for your 2026 compact build.
How to Choose an SFX Power Supply
-
Match 80 Plus Efficiency
Check the 80 Plus efficiency certification on the specification sheet. Small-form-factor enclosures trap heat rapidly because airflow space remains limited. Selecting an 80 Plus Gold or 80 Plus Platinum unit reduces wasted thermal energy during AC-to-DC conversion. Basic everyday systems operate adequately on 80 Plus Bronze ratings. For compact builds where internal heat management is critical, look at units like the SilverStone 700W Platinum SFX Power Supply. Higher efficiency ratings keep internal power supply components cooler during heavy system operation.
-
Calculate Continuous Wattage Needs
Review continuous wattage specifications to match your exact component draw. SFX power supplies range from 300W up to 850W. Low-demand office systems or compact home servers run reliably on units like the SilverStone 300W SFX Bronze Power Supply. High-demand configurations with discrete gaming hardware require 750W or 850W capacities to absorb component power spikes. Compare the total rated power against your estimated CPU and GPU consumption. Never choose a wattage ceiling below your hardware requirements, because continuous output guarantees stable electrical delivery under load.
-
Verify PCIe Power Specifications
Examine the PCIe connector standards and ratings when powering modern graphics hardware. Standard older power supplies use traditional 8-pin PCIe cables. If you assemble a modern small-form-factor build with newer graphics cards, verify dedicated connector standards. The Cooler Master V750 SFX Gold PCIe 5.1 PSU specifies PCIe 5.1 compatibility with right-angle ATX 3.1 cabling supporting up to 450W GPU delivery. Selecting native PCIe 5.1 connectivity eliminates bulky external adapter plugs, saving essential clearance inside cramped Mini-ITX cases while ensuring proper graphics power handling.
-
Inspect Voltage Regulation Limits
Look for published voltage regulation specifications on the product sheet. Standard ATX specifications permit rail fluctuations up to positive or negative 5%. Tighter regulation protects sensitive computer components from sudden voltage drops when your hardware shifts between idle and full workload states. Premium units, such as the SilverStone 750W Gold SFX Power Supply, feature strict ±3% voltage regulation alongside Japanese capacitors. If you run sensitive, high-performance PC components inside small cases, strict voltage tolerances ensure stable delivery across all internal electrical lines.
-
Check Manufacturer Warranty Terms
Check the manufacturer warranty term listed in the product specifications. SFX power supplies run hotter than larger desktop power units due to compact internal component density. A lengthy factory warranty confirms component quality and manufacturer confidence in continuous operation over time. For example, the EVGA SuperNOVA 850 GM SFX Power Supply specifies a 10-year warranty. If you plan to keep your small-form-factor system running across multiple hardware upgrade cycles, evaluate the published warranty duration before finalizing your power supply purchase.
-
Review Cable Wire Gauge
Check the wiring gauge specifications on modular power leads. High-draw hardware pulls considerable current through compact internal wires. Heavier conductor thickness prevents resistance buildup and ensures safe thermal performance during sustained maximum power output. The Lian Li SP850 850W Gold SFX Power Supply lists 16 AWG wiring on its product specification sheet. Choosing 16 AWG conductors over lighter gauge wiring suits builders running high-wattage components inside dense enclosures where heat dissipation from power cables requires careful management.
Frequently asked questions
Can you use an SFX power supply in a standard ATX computer case?
Yes, you can use an SFX power supply in an ATX chassis by installing an ATX adapter bracket. Some models, such as the SilverStone SST-ST30SF V2, include this bracket in the box. Using a compact power unit gives you extra clearance inside larger cases for custom liquid-cooling tubing or storage drives, though you must check that the shorter modular cables reach your motherboard headers.
What is the difference between SFX and SFX-L power supplies?
SFX-L chassis feature a longer depth to house a larger cooling fan. While standard SFX units maintain a length of 3.94 inches, SFX-L models like the SilverStone SST-SX700-LPT extend to 5.12 inches to accommodate a 120mm fan. You get quieter thermal performance from the broader fan blades, but you must ensure your case has sufficient internal clearance behind the power supply bracket for cable management.
How much wattage do you need for a small-form-factor gaming PC?
Your required wattage depends strictly on the power demands of your processor and graphics card. For entry-level or media builds, a 300W or 450W power supply handles the workload reliably. Mid-range systems with dedicated graphics typically operate best on 700W units like the SilverStone SST-SX700-G. High-demand components require 750W or 850W power supplies, such as the EVGA 123-GM-0850-X1, to prevent system shutdowns during peak draw.
Does an SFX power supply support modern PCIe 5.1 graphics cards?
Select SFX power supplies offer dedicated hardware support for the PCIe 5.1 specification. The Cooler Master MPY-7501-SFHAGV-3U1 includes ATX 3.1 right-angle cabling designed to supply up to 450W directly to modern graphics cards. If you install an older SFX power supply lacking this dedicated connector, you must use standard 8-pin PCIe cables paired with the adapter that came with your graphics card.
Why do some SFX power supplies use 16 AWG cables?
Thicker 16 AWG wiring handles higher electrical current with lower heat generation and less voltage drop. Models like the Lian Li SP850B incorporate 16 AWG wire gauge sizes to sustain demanding 850-watt power delivery safely in dense chassis environments. Because compact computer cases restrict natural convective airflow, heavier-gauge wiring ensures stable voltage delivery without overheating your modular cable bundles during sustained power delivery.
Are all SFX power supply cables modular?
Not every SFX power supply features modular cabling, though many compact units do. Fully modular models like the SilverStone SST-SX700-G and Lian Li SP750 let you plug in only the specific harnesses you need, reducing clutter in cramped cases. In contrast, fixed-cable units require you to store unused wires inside the chassis, which can impede airflow in extremely tight small-form-factor enclosures.
How do zero-RPM and semi-passive fan modes work on SFX power supplies?
Zero-RPM or semi-passive cooling modes keep the power supply fan completely stopped during low electrical loads. Units such as the SilverStone PS-SX750-PT-X and Lian Li SP750 operate silently until component temperatures or power output cross an internal threshold. Once power consumption rises during heavy computing or gaming, the fan spins up automatically to dissipate heat from the internal components.