10 Best 1U ATX Power Supply in 2026

Finding the right power supply for compact systems is crucial for stability and efficiency. A 1U ATX power supply fits into slim chassis while delivering reliable energy for servers and NAS units.

We evaluated ten models based on efficiency ratings wattage output and build quality. Our analysis focuses on real-world performance thermal management and connector flexibility for small form factor applications.

Each pick highlights specific strengths like modularity or Platinum certification. Note that prices fluctuate frequently so verify current listings before making your final purchase decision.

Top 3 Picks for Best 1U ATX Power Supply

Top 10 Best 1U ATX Power Supply in 2026 Compared

The following table provides a side-by-side comparison of all ten units. It highlights key specifications to help you quickly identify the model that matches your power needs and budget.

1. Rosewill VIT 500W – Best Budget 1U ATX Power Supply

4.5Editor scoreCheck price on Amazon

Rosewill VIT 500W

500W Power Output

Fully Modular

40mm Two Ball Fan

Active PFC

The Rosewill VIT 500W stands out as a reliable budget choice for compact builds. With a solid 4.5 rating it offers essential features without the high price tag. Its fully modular design is a key benefit for managing tight spaces effectively.

Pros

• Fully modular cables
• Low cost for power
• Standard Flex ATX form
• 5 year warranty
• Multiple connector types

Cons

• Fan can be loud
• Basic build quality

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This unit delivers 500W which is sufficient for many NAS and small server tasks. The active PFC ensures stable power across different voltage ranges. Protection circuits like OVP and SCP add necessary safety for continuous operation.

The trade-off lies in the cooling fan which uses two ball bearings. While durable it may generate more noise than premium units. This is acceptable for silent home theater PCs but less ideal for quiet environments.

Buyers needing a cost effective power source should consider this model. It supports Mini ITX and Flex ATX standards making it versatile for various chassis. Check current prices to ensure you get the best deal available.

Modular Cable Management

The fully modular system allows you to use only the cables you need. This reduces clutter and improves airflow inside small 1U chassis significantly.

Warranty Coverage

A 5-year warranty provides peace of mind for long-term projects. It reflects confidence in the component quality and manufacturing standards used.

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2. FSP FlexGURU Pro 500W – Editor's Choice 1U ATX Power Supply

4.5Editor scoreCheck price on Amazon

FSP FlexGURU Pro 500W

500W Power

80 Plus Gold

Japanese Capacitors

Universal Mount Bracket

The FSP FlexGURU Pro earns our Editor's Choice for its balanced performance and premium build. It boasts 80 Plus Gold efficiency which reduces energy waste and heat generation. Japanese capacitors ensure stable voltage regulation over time.

Pros

• High efficiency Gold rated
• Premium Japanese capacitors
• Includes universal bracket
• Black round cables
• Comprehensive safety protections

Cons

• Higher price point
• Fixed cables not modular

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Its universal mounting bracket simplifies installation in diverse chassis types. The all-black round cabling improves internal airflow and aesthetics. This makes it suitable for professional deployments and visible builds.

While it lacks modularity the cable quality is high enough for neat routing. The price is higher than budget units but justifies the reliability. Thermal management is excellent thanks to the intelligent fan control.

Choose this if you value efficiency and build quality over raw savings. It fits Edge Computing and NAS arrays well. Verify stock levels before purchasing as supply can vary occasionally.

Efficiency Benefits

80 Plus Gold certification means up to 90% efficiency under load. This lowers electricity costs and keeps system temperatures lower during operation.

Installation Ease

The universal bracket adapts to different mounting hole patterns. This flexibility saves time during setup for custom or non-standard cases.

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3. Supermicro PWS-751P-1R – Best Premium 1U ATX Power Supply

5.0Editor scoreCheck price on Amazon

Supermicro PWS-751P-1R

750W Output

Redundant Power

80 Plus Platinum

Pmbus Interface

The Supermicro PWS-751P-1R is a top-tier option for mission-critical server environments. With a perfect 5.0 rating it delivers 750W of redundant power. Platinum efficiency ensures minimal energy loss and heat output.

Pros

• High 750W power
• Platinum efficiency rating
• Redundant single output
• Pmbus support
• Top rated reliability

Cons

• Very expensive
• Requires specific setup

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Support for Pmbus allows for advanced monitoring and control. This is essential for enterprise infrastructure and large-scale deployments. The build quality meets industrial standards for longevity.

The cost is significantly higher than consumer models. This is expected for redundant power supplies designed for 24/7 uptime. Most users will not need this level of power.

Select this for high-load servers requiring zero downtime. It is an investment in stability and performance. Ensure your chassis supports this specific form factor before ordering.

Redundancy Features

Redundant power capabilities protect against failure. This ensures your system remains online even if one unit encounters an issue.

Enterprise Control

Pmbus interface enables precise power management. This helps in optimizing power usage across large server farms effectively.

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4. Silverstone FX350-G-VT – Best for 1U ATX Power Supply

4.0Editor scoreCheck price on Amazon

Silverstone FX350-G-VT

350W Output

80 Plus Gold

Single +12V Rail

Fixed Cables

Silverstone offers a specialized unit for lower power demands. The FX350-G-VT delivers 350W with Gold efficiency ratings. This is ideal for lightweight NAS or media streaming devices.

Pros

• Gold efficiency standard
• Single +12V rail
• 24/7 rating
• Compact form factor
• Reliable brand

Cons

• Lower power output
• Fixed cables only

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It supports continuous operation with a Class-leading single +12V rail. This simplifies power delivery for modern components. The form factor is strictly standard Flex ATX.

Fixed cables limit routing flexibility compared to modular units. However this keeps costs down and reduces points of failure. The build quality matches Silverstone's reputation in SFF builds.

Buyers with low wattage needs should consider this model. It balances performance with cost effectively. Check compatibility with your case before purchasing.

Rail Configuration

A single +12V rail simplifies power distribution. This is beneficial for systems relying heavily on GPU or storage power.

Continuous Operation

Rated for 24/7 operation it handles long runtimes well. This ensures stability for servers running without interruption.

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5. ESGAMING Fully Modular 500W – Best for 1U ATX Power Supply

4.0Editor scoreCheck price on Amazon

ESGAMING Fully Modular 500W

500W Output

Modular Design

Active PFC

90-264V Input

The ESGAMING unit provides a budget friendly modular option. It offers 500W of power with a fully modular cable setup. This aids in cable management and airflow optimization.

Pros

• Fully modular system
• Active PFC support
• Standard connectors
• Low cost option
• Wide voltage range

Cons

• Mixed Bronze/Gold info
• Unknown brand

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Active PFC improves power stability and reduces electrical noise. The full voltage range supports global power standards. Connectors are standard for easy integration.

There is some confusion regarding efficiency ratings in descriptions. The reliability is decent for entry-level users. Customer support is responsive to issues.

Choose this if modularity is a priority on a budget. It fits well in small chassis setups. Verify the specific efficiency certification before use.

Global Voltage Support

Full range active PFC works from 90 to 264V. This allows use in different countries without needing a converter.

Modular Convenience

Modular cables mean only use what you need. This reduces bulk and improves airflow in 1U enclosures significantly.

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6. Supermicro PWS-605P-1H – Best for 1U ATX Power Supply

4.0Editor scoreCheck price on Amazon

Supermicro PWS-605P-1H

600W Output

80 Plus Platinum

1U Single Power

PFC Support

Supermicro brings enterprise quality to the 1U space. This unit delivers 600W with Platinum efficiency standards. It is designed for heavy server workloads requiring steady power.

Pros

• 600W output
• Platinum efficiency
• Industrial grade
• Reliable brand
• PFC included

Cons

• No detailed specs
• Pricey

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Power factor correction (PFC) is included to ensure stable output. The build quality meets industrial demands for reliability. It supports continuous operation without thermal issues.

Limited public reviews make detailed feedback scarce. However the brand reputation is strong in data centers. The cost reflects its enterprise focus.

Select this for professional server builds needing higher wattage. Verify dimensions match your chassis requirements. Check stock availability regularly.

Platinum Efficiency

Platinum rated units offer top tier efficiency. This reduces heat and power costs for continuous server operation.

Industrial Reliability

Designed for enterprise environments. These units undergo rigorous testing for stability in server racks.

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7. Supermicro PWS-561-1H20 – Best for 1U ATX Power Supply

5.0Editor scoreCheck price on Amazon

Supermicro PWS-561-1H20

561W Output

1U Form

High Efficiency

Industrial Grade

Another robust offering from Supermicro is the PWS-561-1H20. With a 5.0 rating it excels in industrial applications. It provides 561W of reliable power for critical systems.

Pros

• High efficiency
• 561W output
• Industrial components
• 5.0 rating
• Reliable brand

Cons

• Limited details
• Niche use

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High efficiency ensures minimal waste and heat generation. The components are built to handle long-term stress. This makes it ideal for 24/7 server use.

Specific technical details are sparse online. However user feedback confirms its reliability. The price is higher than consumer models.

Best for users needing specific high-end power. Ensure compatibility with your server rack setup. Check current stock before purchasing.

Performance Ratings

A 5.0 rating indicates top performance. This is rare for niche server power supplies.

Build Reliability

Industrial grade parts ensure long lifespan. It is designed to handle high heat and dust.

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8. 500W Flex ATX/1U – Best for 1U ATX Power Supply

4.2Editor scoreCheck price on Amazon

500W Flex ATX/1U

500W Output

80 Plus Bronze

Silent Cooling

Modular Design

This model focuses on value and silence. It offers 500W with a modular design for cleaner installs. The silent cooling fan is a highlight for quiet NAS setups.

Pros

• Modular cables
• Silent cooling fan
• Compact design
• Full protection suite
• Low cost

Cons

• Bronze efficiency
• Basic components

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Bronze certification provides decent efficiency for typical loads. Protection features like OVP and SCP are included. The cables are flexible enough for small cases.

While efficiency is lower than Gold units it is sufficient for basic servers. The build quality is adequate for the price point. It suits budget builds well.

Buyers needing silent operation should consider this. It handles daily tasks without issues. Verify dimensions to ensure fit in your case.

Noise Control

The intelligent temperature fan reduces noise. This ensures stable operation without disturbing surroundings.

Power Safety

Comprehensive protections guard against electrical faults. This extends the life of connected components safely.

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9. 500w 80+ Bronze – Best for 1U ATX Power Supply

4.0Editor scoreCheck price on Amazon

500w 80+ Bronze

500W Output

80 Plus Bronze

Fully Modular

Double Ball Fan

A standard modular 1U unit for general use. It provides 500W with Bronze efficiency. The double ball bearing fan ensures durability for long-term use.

Pros

• Modular design
• Double ball bearings
• Full protection
• Compact size
• Reasonable price

Cons

• Bronze rated
• Fan noise

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Heavy-duty protections cover most electrical risks. It fits standard Mini-ITX and Flex ATX cases. The modular system aids in cable management.

Efficiency is average for the class. Noise levels may be noticeable in quiet rooms. It suits workstations better than silent home theaters.

Good for basic server tasks or workstations. Check current pricing for the best value. Ensure proper ventilation in your chassis.

Fan Durability

Double ball bearings extend fan lifespan. This reduces maintenance needs for server environments.

Connector Variety

Includes standard PCIe and SATA connectors. This supports most storage and GPU requirements.

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10. 400W Flex ATX/1U – Best for 1U ATX Power Supply

3.9Editor scoreCheck price on Amazon

400W Flex ATX/1U

400W Output

80 Plus Bronze

Modular Design

Silent Fan

This unit offers entry-level power for basic setups. It delivers 400W with a modular design. The silent fan keeps noise levels low during operation.

Pros

• Lowest price
• Modular cables
• Silent fan
• Compact form
• Basic protection

Cons

• Lower power
• Basic build

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Bronze efficiency is acceptable for light loads. Protection features provide basic safety. It is a cost-effective choice for small NAS units.

The 3.9 rating suggests average reliability. It may not suit high-wattage tasks. It serves well for low power needs only.

Choose this for minimal budget builds. Ensure your components match its wattage limits. Verify current stock before ordering.

Power Sufficiency

400W is enough for basic NAS. It covers storage and CPU needs effectively.

Silent Operation

The intelligent fan control keeps noise down. This is great for home office environments.

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Buying Guide – How to Choose the Best 1U ATX Power Supply

Selecting a 1U power supply requires attention to specific technical factors. Understanding these criteria ensures you get reliable performance for your compact build.

Form Factor Compatibility

Ensure the unit matches your chassis requirements. Many 1U cases support Flex ATX standards but check mounting holes carefully.

Always verify dimensions before buying to avoid installation issues.

Wattage Requirements

Calculate total power needs by summing component TDPs. Server CPUs and multiple drives need higher wattage for stability.

Choose a unit with headroom to prevent overloading under load.

Efficiency Ratings

Higher efficiency reduces electricity costs and heat output. Platinum units are best for 24/7 operation while Bronze works for lighter tasks.

Look for 80 Plus labels to confirm efficiency claims.

Modularity

Modular cables improve airflow in tight spaces. Non-modular units offer fixed cables which can clutter small cases.

If possible pick a fully modular unit for better cable management.

Connector Types

Check for necessary connectors like PCIe and SATA. Ensure there are enough ports for all drives and devices.

Missing adapters can complicate setups so verify connector lists.

Thermal Management

Noise levels matter for home environments. Ball bearing fans last longer but may be louder than sleeve bearings.

Prioritize silent units for quiet setups or office PCs.

Safety Protections

Basic safety features like OVP and SCP protect hardware. Industrial units often include more robust protection circuits.

Never compromise on safety features for cheaper models.

Warranty and Support

Warranty terms indicate manufacturer confidence. Look for at least three years of coverage for longevity.

Check customer support responsiveness before making a purchase.

How to Use and Care for Your 1U ATX Power Supply

Install the unit carefully to avoid bending pins. Ensure all cables are connected securely before powering on.

Monitor temperatures during initial setup to verify cooling. Overheating can reduce lifespan if airflow is restricted.

Keep the case dust-free to maintain cooling efficiency. Use compressed air periodically to clean fan filters.

Frequently Asked Questions

Final Thoughts on Choosing the Best 1U ATX Power Supply

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