Rosewill VIT 500W
4.5Editor score
Fully modular cable design
500W power output
5 year warranty coverage
In this guide
Finding the right power supply for small form factor builds can be challenging. A 1U ATX power supply must deliver stable power while fitting into tight spaces. We review top models to help you choose the best fit for your system.
We compared these products based on efficiency ratings, wattage capacity, and build quality. Our analysis includes features like modular cables and fan noise levels. This list covers options for NAS, servers, and HTPC setups.
Each pick highlights key strengths and potential drawbacks for your specific needs. Prices and availability may change over time. Always verify current specs before purchasing to ensure compatibility with your components and case.
Top 3 Picks for Best 1U ATX Power Supply
FSP FlexGURU Pro 500W
4.5Editor score
80 Plus Gold efficiency
Japanese capacitors used
Universal mounting bracket
Supermicro PWS-751P-1R
5.0Editor score
750W power capacity
Redundant power support
Platinum efficiency rating
Top 10 Best 1U ATX Power Supply in 2026 Compared
Below you will find a detailed side-by-side comparison of all ten products reviewed in this guide. Each entry includes key specifications to help you quickly identify the right unit for your needs.
ProductsSpecificationsEditor scorePrice
Best Budget
Rosewill VIT 500W
500W power output
Fully modular cables
5 year warranty
40mm ball fan
4.5Editor score
Editor's Choice
FSP FlexGURU Pro 500W
80 Plus Gold certified
Japanese capacitors
Universal mounting bracket
40mm 2ball fan
4.5Editor score
Best Premium
Silverstone FX350-G-VT
350W continuous power
80 Plus Gold certified
Fixed cables included
Single 12V rail
4.0Editor score
ESGAMING Fully Modular 500W
500W power output
Fully modular design
Active PFC support
80 Plus Bronze rated
4.0Editor score
Supermicro PWS-605P-1H
600W power output
80 Plus Platinum
Single output type
PFC technology
4.5Editor score
Supermicro PWS-751P-1R
750W power output
Redundant design
80 Plus Platinum
PMBus support
5.0Editor score
Supermicro PWS-561-1H20
Ablecom PWS series
1U form factor
High wattage
Server grade build
5.0Editor score
500W Flex ATX/1U
500W power output
Fully modular design
80 Plus Bronze
Silent cooling fan
4.2Editor score
500w 80+ Bronze
500W power output
Fully modular design
80 Plus Bronze
40mm double ball fan
4.0Editor score
400W Flex ATX/1U
400W power output
Fully modular design
80 Plus Bronze
Silent cooling fan
3.9Editor score
1. FSP FlexGURU Pro 500W – Best Overall 1U ATX Power Supply
FSP FlexGURU Pro 500W
80 Plus Gold certified
Japanese main capacitors
Universal mounting bracket
40mm 2ball fan
This FSP FlexGURU Pro 500W stands out as a top choice for small form factor builds. It delivers reliable power with up to 90% efficiency under typical loads. The use of Japanese electrolytic capacitors ensures precise voltage regulation and long-term reliability.
Pros
- Excellent thermal management
- Premium component quality
- Clean all-black cabling
- Flexible cable routing
- Stable voltage regulation
Cons
- Higher price point
- Limited wattage options
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The thermal management system features a 40mm 2ball bearing fan with intelligent speed control. This keeps critical components cool without excessive noise. The all-black round cabling simplifies routing in tight chassis spaces for a clean aesthetic.
While the price is higher than some competitors, the build quality justifies the cost. Universal mounting brackets make installation straightforward across various SFF builds and NAS chassis. Safety protections include UVP, OVP, SCP, OPP, and OTP for comprehensive security.
This PSU is ideal for users prioritizing efficiency and build quality in compact systems. It suits Edge Computing, NAS arrays, and HTPC setups well. Consider this model if you need stable power for continuous operation.
Efficiency and Energy Savings
80 Plus Gold certification means lower energy consumption and reduced heat output. This translates to lower operating costs and stable system performance over time.
Premium Component Reliability
Japanese main capacitors ensure precise voltage regulation. This design supports dependable long-term reliability under continuous operation for your critical components.
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2. Rosewill VIT 500W – Best Budget 1U ATX Power Supply
Rosewill VIT 500W
500W power output
Fully modular cables
5 year warranty
40mm ball bearing fan
The Rosewill VIT 500W offers a compelling balance of price and features for budget-conscious builders. It provides 500W power output with a fully modular design to reduce clutter. Active PFC ensures efficient power delivery across a full voltage range.
Pros
- Affordable price point
- Full modular cable design
- Strong warranty coverage
- Active PFC support
- Multiple connector types
Cons
- Basic build materials
- Limited noise control
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This unit includes various connector types like SATA, PCIe, and Molex for versatile component support. The 40mm fan uses two ball bearings for durability and is governed by thermal speed control. A five-year warranty adds peace of mind for users.
Build materials are basic compared to premium models but functional for most SFF applications. The fully modular design helps improve airflow in tight spaces. It is suitable for Mini Server, NAS, and small form factor needs.
This PSU is best for users needing reliable power without high cost. It fits well in Mini ITX or Flex ATX chassis. Choose this for cost-effective small form factor builds requiring modular cabling.
Modular Cable Management
Fully modular power supply design reduces cable clutter. This improves internal airflow and makes installation easier in compact chassis.
Protection Features
Includes over voltage, over power, over current, and short circuit protection. These safeguards protect your components from electrical failures.
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3. Supermicro PWS-751P-1R – Best Premium 1U ATX Power Supply
Supermicro PWS-751P-1R
750W power capacity
Redundant power support
Platinum efficiency rating
PMBus monitoring
The Supermicro PWS-751P-1R is a high-end choice for enterprise or mission-critical systems. It delivers 750W power capacity with Platinum efficiency. The redundant design ensures continuous operation even if one unit fails.
Pros
- High power capacity
- Redundant design
- Platinum efficiency
- PMBus control
- Enterprise grade quality
Cons
- High cost
- Specialized use case
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PMBus support allows for advanced monitoring and control of power parameters. This single output power supply fits standard 1U rackmount servers. Its build quality meets the demands of continuous heavy-duty workloads.
This unit comes with a premium price tag suited for professional environments. It is not typically needed for home HTPC setups. The reliability and efficiency justify the investment for server deployments.
Ideal for users needing maximum reliability and power headroom. This PSU supports server rack deployments requiring redundant power. Choose this if uptime and efficiency are top priorities.
Redundant Power Reliability
Redundant power supply ensures system uptime. If one unit fails, the other continues operation to maintain service.
Advanced Monitoring
PMBus technology allows for detailed power monitoring. This helps administrators track power consumption and health status effectively.
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4. Silverstone FX350-G-VT – Compact Power Solution
Silverstone FX350-G-VT
350W continuous power
80 Plus Gold certified
Fixed cables included
Single 12V rail
The Silverstone FX350-G-VT provides 350W continuous power output at 40℃ operating temperature. It is rated for 24/7 operation with 80 Plus Gold certification. The single +12V rail class-leading design offers stable power distribution.
Pros
- Gold efficiency rating
- Single 12V rail
- Compact size
- Reliable performance
- Good cable length
Cons
- Fixed cables only
- Lower wattage limit
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This unit supports standard Flex ATX form factor with fixed cables for simplicity. Active PFC ensures stable power delivery and reduced electrical interference. It supports PCIe 6pin connectors for moderate GPU needs.
Fixed cables may limit routing flexibility in very tight spaces. However, the Gold efficiency ensures low heat output and energy savings. It is suitable for small systems with moderate power requirements.
Best for users needing a reliable compact PSU for SFF builds. This model works well for low-power NAS or HTPC systems. Consider this if you prioritize efficiency over modularity.
24/7 Operation Rating
Rated for continuous operation at 40℃. This ensures stability for systems running long periods without rest.
Single 12V Rail Design
Class-leading single +12V rail delivers consistent power. This simplifies power distribution for system components.
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5. ESGAMING Fully Modular 500W – Efficient Compact Choice
ESGAMING Fully Modular 500W
500W power output
Fully modular cables
Active PFC support
80 Plus Bronze rated
The ESGAMING Fully Modular unit offers 500W power with a fully modular cable system. This simplifies installation and improves airflow in compact 1U chassis. Active PFC provides improved power stability across full voltage range.
Pros
- Modular cable design
- Active PFC included
- Budget friendly
- Compact 1U size
- Multiple connector types
Cons
- Bronze efficiency level
- Basic build quality
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Connectors include 20+4pin motherboard, 8pin CPU, PCIe, SATA, and PATA. The design ensures reliable 24/7 server operation with reduced energy waste. It is suited for Mini Server, NAS, and small form factor PC builds.
Efficiency is Bronze level, which is lower than Gold or Platinum options. However, the modular design helps keep the build clean. Customer support is available for purchase issues or concerns.
This PSU suits users needing modular convenience at a low cost. It works well for entry-level NAS or SFF systems. Consider this if modularity is a priority over peak efficiency.
Active PFC Benefits
APFC Full Range 90-264V ensures stable power. This reduces electrical interference and delivers cleaner output.
Compact Chassis Fit
Fits 1U chassis with modular design. This improves internal airflow and simplifies cable management.
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6. Supermicro PWS-605P-1H – High Efficiency Server Unit
Supermicro PWS-605P-1H
600W power output
80 Plus Platinum
Single output type
PFC technology
The Supermicro PWS-605P-1H delivers 600W with 80 Plus Platinum efficiency. It is designed for single power supply configurations in 1U rackmount servers. PFC technology ensures efficient power conversion and stability.
Pros
- Platinum efficiency
- High power capacity
- Server grade build
- PFC technology
- Reliable brand
Cons
- Non-modular cables
- Higher cost
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This unit is built for enterprise environments requiring robust power. The single output format simplifies integration into specific server chassis. Its high efficiency reduces energy costs over time.
Fixed cables may limit flexibility compared to modular units. However, the Platinum rating ensures low heat output. This is a reliable choice for server deployments needing stable power.
Best for server users prioritizing efficiency and power headroom. This model fits single PSU configurations well. Consider this for enterprise NAS or rack server needs.
Platinum Efficiency Benefits
80 Plus Platinum efficiency minimizes energy waste. This lowers heat generation and operating costs significantly.
Single Power Design
Designed for single output configurations. This simplifies integration for specific server chassis.
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7. Supermicro PWS-561-1H20 – Enterprise Power Option
Supermicro PWS-561-1H20
Ablecom PWS series
1U form factor
High wattage
Server grade build
The Supermicro PWS-561-1H20 belongs to the Ablecom PWS series designed for servers. It offers high wattage output within a standard 1U form factor. This unit is built for professional environments requiring consistent performance.
Pros
- Enterprise grade reliability
- High wattage output
- 1U rack fit
- Stable performance
- Professional build
Cons
- Limited availability
- Premium pricing
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Its design ensures stable power delivery for critical workloads. The build quality matches enterprise standards for durability. It integrates into specific server chassis requiring PWS series models.
This model may be harder to find than consumer options. However, its performance justifies the investment for server needs. It is a solid choice for rackmount deployments.
Ideal for enterprise users needing server-grade reliability. This PSU fits high-demand NAS or server chassis. Choose this for professional server infrastructure.
Server Grade Build Quality
Built to match enterprise standards. This ensures durability and consistent performance under load.
High Wattage Delivery
Provides high wattage output for demanding systems. This supports power-hungry server components effectively.
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8. 500W Flex ATX/1U – Versatile Small Form Factor PSU
500W Flex ATX/1U
500W power output
Fully modular design
80 Plus Bronze
Silent cooling fan
This 500W Flex ATX/1U Power Supply delivers 85% energy efficiency with Bronze certification. It features a fully modular cable system for easier management. A silent cooling fan with intelligent temperature control ensures quiet operation.
Pros
- Fully modular cables
- Compact 1U size
- Silent cooling fan
- Multiple protection safeguards
- Durable components
Cons
- Bronze efficiency
- Limited wattage headroom
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Safety protections include OVP, OCP, OPP, and SCP to safeguard components. It fits 1U rackmount servers, NAS systems, and HTPC builds. Premium capacitors ensure stable output and long-lasting durability.
The Bronze rating means slightly higher heat output than Gold models. However, the modular design helps manage airflow effectively. It suits small form factor builds needing reliable power.
This PSU is best for users needing modular cables and silent operation. It works well for home NAS or HTPC setups. Consider this for compact builds with moderate power needs.
Silent Cooling Operation
Equipped with low noise fan and intelligent temperature control. This ensures quiet and stable operations.
Modular Design
Fully modular cable system for cleaner builds. This improves airflow inside compact cases.
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9. 500w 80+ Bronze – Budget Modular PSU
500w 80+ Bronze
500W power output
Fully modular design
80 Plus Bronze
40mm double ball fan
This 500w PSU offers fully modular cable design for compact cases. It delivers Bronze efficiency with Full-Range Active PFC for stable power. The 40mm double ball bearing fan ensures durability.
Pros
- Modular cable design
- Active PFC support
- Affordable price
- Double ball fan
- Multiple connector types
Cons
- Bronze efficiency level
- Basic build materials
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Connectors include 20+4pin, 8pin CPU, PCIe, SATA, and Molex. Heavy-duty protection includes SCP, UVP, OPP, and OVP safeguards. It suits mini servers, NAS, HTPC, and rack-mounted systems.
Bronze efficiency is lower than Gold or Platinum options. However, the modular design simplifies routing effectively. It is a budget choice for small builds needing flexibility.
Best for users needing modularity on a tight budget. This unit works well for entry-level SFF systems. Consider this if efficiency is less critical than cable management.
Full-Range Active PFC
Supports Full-Range Active PFC for 90-264V. This ensures stable power delivery and reduced interference.
Double Ball Fan
Uses a 40mm double ball bearing fan. This ensures durability for long-term cooling.
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10. 400W Flex ATX/1U – Entry-Level Compact Unit
400W Flex ATX/1U
400W power output
Fully modular design
80 Plus Bronze
Silent cooling fan
This 400W unit provides 85% energy efficiency with Bronze certification. It features a fully modular cable system for easier management in small cases. A silent cooling fan with intelligent temperature control reduces noise.
Pros
- Modular cable system
- Compact 1U size
- Silent cooling fan
- Safety protections included
- Durable capacitors
Cons
- Bronze efficiency rating
- Lower wattage capacity
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Protections include OVP, OCP, OPP, and SCP safeguards. Premium capacitors ensure stable output and long-lasting durability. It fits 1U rackmount servers, NAS systems, and HTPC builds.
Lower wattage limits high-power GPU or server component support. However, the modular design helps manage cable clutter. It is suitable for low-power NAS or HTPC setups.
Best for users needing a budget entry point for modular PSUs. This model works well for small form factor builds. Consider this if 400W meets your system needs.
Silent Cooling
Equipped with low noise fan and intelligent temperature control. This ensures quiet and stable operations.
Modular Design
Fully modular cable system for easier management. This improves airflow inside compact cases.
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Buying Guide – How to Choose the Best 1U ATX Power Supply
Choosing a 1U ATX power supply requires careful consideration of several factors. Below we break down the key aspects to help you make an informed decision.
Power Output
Select a unit with sufficient wattage for your components. Higher wattage allows for better headroom. This ensures stable performance under heavy loads.
Efficiency Rating
Look for 80 Plus Gold or Platinum certifications. Higher ratings mean lower energy waste and heat output. This reduces operating costs and improves system stability.
Modular vs Fixed Cables
Fully modular designs simplify cable routing. They improve airflow in compact 1U cases. Fixed cables may reduce cost but limit flexibility.
Connector Types
Ensure the unit has necessary connectors like PCIe and SATA. Some low-profile cards may need specific power options. Verify compatibility with your motherboard and drives.
Form Factor Compatibility
Check dimensions against your case. 1U units must fit specific height. Standard Flex ATX dimensions help ensure proper fit.
Noise Levels
Smaller fans often spin faster and generate more noise. Look for intelligent fan control or larger fans. This helps maintain quiet operation in small builds.
Brand Reputation
Choose established brands for reliability. They offer better quality control and support. This minimizes risks of premature failure.
Safety Protections
Look for OVP, OCP, and SCP safeguards. These protect against electrical failures. They help prevent damage to expensive components.
How to Use and Care for Your 1U ATX Power Supply
First install the PSU in a well-ventilated area. Ensure all cables are secured properly. This minimizes vibration and connection issues.
Regularly clean dust from the fan using compressed air. Dust accumulation can lead to overheating. This helps maintain cooling efficiency.
Avoid overloading the unit beyond its capacity. Monitor power draw to stay within limits. This extends the lifespan of the PSU.
Frequently Asked Questions
Can I use a standard ATX power supply in a 1U case?
No, standard ATX units are too tall for 1U cases. You need a 1U specific PSU designed for that height. This ensures proper fit and mounting compatibility.
Why is efficiency rating important?
Higher efficiency reduces energy waste and heat output. This saves money and lowers operating costs. It also ensures stable performance for critical workloads.
Are modular cables necessary?
Modular cables improve airflow and simplify routing. They are ideal for tight 1U cases. Fixed cables may work but limit flexibility.
What connectors do I need?
Check your motherboard and GPU for power requirements. Ensure you have sufficient PCIe and SATA connectors. This avoids compatibility issues during build.
Can I use this for a NAS?
Yes, many 1U PSUs are designed for NAS systems. Look for reliable brands and stability ratings. This ensures 24/7 uptime for storage.
How loud are these units?
Noise varies by model and fan design. Higher wattage units may be louder. Look for intelligent speed control for quieter operation.
Is a longer warranty better?
Yes, longer warranties indicate manufacturer confidence. It protects against premature failure. This provides peace of mind for critical systems.
Do I need active PFC?
Active PFC improves power efficiency and stability. It is standard on most modern units. Ensure your PSU has this feature for reliable operation.
Final Thoughts on Choosing the Best 1U ATX Power Supply
We reviewed ten options ranging from budget to premium solutions. The FSP FlexGURU Pro 500W leads overall with efficiency and build quality. The Rosewill VIT 500W offers strong value for those watching costs.
Prioritize efficiency and modular design for compact builds. Ensure connectors match your system components. These factors determine long-term stability and ease of use.
Always check current prices and availability before purchasing. Specifications may vary slightly. Verify compatibility for your specific 1U chassis model.