Best 1U ATX Power Supplies for Small Form Factor PCs
Choosing a compact 1U ATX power supply requires balancing efficiency, modularity, and reliability for small form factor builds. This guide highlights five notable options, covering fully modular designs, 80 Plus certifications, and safe operation in POS, AIO, NAS, and mini-server environments.
Summary of Selected Products
| Product | Brand | Form Factor | Wattage | Modular | Key Benefit |
|---|---|---|---|---|---|
| Apevia ITX-PFC500W | Apevia | Mini ITX / Flex ATX | 500W | Fully Modular | High wattage in 1U footprint |
| Apevia ITX-PFC400W | Apevia | Mini ITX / Flex ATX | 400W | Fully Modular | Solid 1U option with robust protections |
| ESGAMING 500W 1U | ESGAMING | 1U Flex ATX | 500W | Fully Modular | 80 Plus Bronze efficiency |
| Ptcliss 600W | Ptcliss | 1U Flex ATX | 600W | Fully Modular | High efficiency with Gold/auto-protection |
| T.F.SKYWINDINTL 600W | T.F.SKYWINDINTL | Flex ATX | 600W | Fully Modular | 600W in compact 1U form |
Apevia ITX-PFC500W Mini ITX Power Supply
Apevia’s ITX-PFC500W delivers 500W in a compact 1U/Flex ATX form factor, featuring full modular cabling and a full-range 90-264V input with active PFC. The supply provides essential protections including OVP, OLP, OCP, OTP, and SCP, helping safeguard POS and small server setups. It includes 20+4pin main power, 8pin CPU, dual 6+2 PCIe, SATA, and Molex connectors, alongside a 40mm fan for cooling in tight enclosures.
Apevia ITX-AP300W Mini-ITX Power Supply
The ITX-AP300W offers 300W of power in a 1U/Flex ATX build with standard Mini-ITX/FLEX ATX compatibility. It includes a 20+4pin main power connector and an 8-pin 12V CPU connector, plus dual SATA and four-pin Molex power cables. A 40mm double-ball bearing fan provides active cooling in compact deployments, with protections covering common fault conditions to maintain stability in light-duty servers or small desktops.
Apevia ITX-PFC400W Mini ITX Power Supply
The ITX-PFC400W provides a reliable 400W output in a space-saving 1U form. It includes Full Range Active PFC with a 90-264V input, modular cabling, 1 x 20+4pin main, 1 x 8pin CPU, PCIe, SATA, and Molex connectors, plus a 40mm cooling fan. Protection mechanisms like OVP, OLP, OCP, OTP, and SCP help maintain stable operation in small form factor builds and POS devices.
ESGAMING 500W 1U/Flex ATX Power Supply
ESGAMING’s 500W 1U/Flex ATX model is 80 Plus Bronze certified, delivering efficiency and reliability for compact servers, NAS, or HTPC setups. It is fully modular to reduce cable clutter and supports typical 1U chassis layouts with a 20+4pin motherboard connection, 8-pin CPU, dual PCIe 6+2, SATA, and 4-pin Molex/pata connectors. The modular design enhances airflow in tight spaces.
T.F.SKYWINDINTL Flex ATX 600W 1U PSU
The 600W Flex ATX power supply from T.F.SKYWINDINTL is designed for 1U servers, POS, and NAS systems. Fully modular cabling supports standard Flex ATX form factors, with cables for 20/24pin mainboard power, CPU 12V, PCIe, SATA, and 4-pin motherboards. It is built for stable operation across 100-240V input, focusing on efficiency and simplified installations in compact rack environments.
Ptcliss 600W Full Modular 1U Flex ATX
Ptcliss 600W is a full modular 1U Flex ATX PSU, suitable for POS, AIO, and small servers. It features 80 Plus Gold efficiency, DC-DC regulation for stable outputs, and Japanese capacitors for durability. The modular design simplifies cable management in tight chassis, while supporting a standard Flex ATX form factor with reliable protection features and robust performance in variable voltage environments.
Buying Guide: Key Purchase Considerations
- Efficiency and certifications: Look for 80 Plus Bronze or Gold ratings to minimize energy waste and heat, especially in always-on 1U servers or NAS boxes.
- Modularity: Fully modular cables simplify cable management, improve airflow, and make installation in compact enclosures easier.
- Form factor compatibility: Confirm the board-to-PSU compatibility with Mini ITX and Flex ATX standards and ensure the unit fits 1U chassis dimensions.
- Connectors and rails: Verify the required motherboard power (20+4 pin), CPU 8-pin, PCIe PCIe 6+2, and storage connectors (SATA/Molex) match your build.
- Protections and reliability: OVP, OCP, SCP, OTP, and OL protections are essential for long-term use in servers and AIO systems.
- Cooling and noise: A compact 40mm fan is common in 1U PSUs; consider units with smart or silent cooling for quiet NAS or media centers.
- Voltage stability: Some models emphasize DC-DC regulation and quality Japanese capacitors for stable output in fluctuating power conditions.
- Future-proofing: If you anticipate higher loads, prefer 500W–600W options with modularity and robust protection sets to accommodate upgrades.
- Service and warranty: Check warranty length and reseller support to ensure long-term reliability.