Apevia ITX-AP300W 300W ITX ATX Alternatives: 6 Similar Picks Compared
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The Apevia ITX-AP300W 300W ITX ATX alternatives list helps you find power supplies that match its compact footprint and low wattage. The original unit delivers reliable 300W output in a tiny 5.91 x 3.21 x 1.59-inch frame, making it ideal for Mini-ITX and 1U cases. Its separable 20+4 and 4+4 connectors support both legacy and modern motherboards, while the 40mm fan keeps noise low. However, you might need more power for heavier components or prefer a different form factor for your specific case.
We selected these 6 alternatives because their specifications overlap with the original in key areas like efficiency, modularity, or connector standards. Some options offer higher wattage for future upgrades, while others provide fully modular cabling for cleaner builds. You may also prefer a different brand for its warranty length or specific ATX version compliance. This guide compares each pick based on published specs, ensuring you find a unit that fits your hardware requirements without compromising on safety features like OVP or OCP.
Our top pick: Apevia 300W Mini-ITX Power Supply.
How these alternatives differ
MSI MAG 850W Fully Modular ATX Power Supply
This MSI unit targets modern ATX builds rather than compact SFF cases. It delivers 850W of power, which is nearly three times the output of the 300W Apevia. The form factor is standard ATX, measuring 12 x 8.75 x 4.92 inches, so it will not fit in Mini-ITX or 1U chassis. It supports ATX 3.1 and PCIe 5.1 standards with a fully modular cable design. You should choose this if you are building a standard desktop with high-power components and need Gold efficiency. It sacrifices compact size for significantly higher wattage and modern connectivity standards.
Corsair RM850x Shift 850W White ATX Power Supply
The Corsair RM850x Shift offers 850W of power in a standard ATX form factor. It measures 6.3 x 5.91 x 3.39 inches, which is much larger than the tiny Apevia unit. This model supports ATX 3.1 and PCIe 5.1, providing modern connectivity for current GPUs. It features 80 Plus Gold efficiency and fully modular cabling. While the Apevia is designed for low-power Mini-ITX systems, this Corsair unit is built for standard ATX cases. You should pick this alternative if you need more power and do not require a small form factor. It provides higher capacity and modern standards at the cost of physical size.
Corsair RM1000x 1000W ATX 3.1 PSU
This Corsair RM1000x delivers 1000W of power, making it a high-end choice for demanding desktops. It uses a standard ATX form factor with dimensions of 2.3 x 3.39 x 5.91 inches. The unit supports ATX 3.1 and PCIe 5.1 standards with fully modular cables. It is significantly more powerful than the 300W Apevia, which is limited to low-draw systems. You should choose this if you are building a high-performance PC with power-hungry components. It offers substantial wattage and modern connectivity but requires a standard ATX case. It is not suitable for compact Mini-ITX builds due to its size and high power output.
Corsair RM1000x Shift 1000W Power Supply
The Corsair RM1000x Shift provides 1000W of power with ATX 3.0 support. It measures 7.09 x 5.91 x 5.08 inches, fitting only in standard ATX cases. This unit is fully modular and offers 80 Plus Gold efficiency. It is designed for high-draw systems that require significant power delivery. The Apevia unit is a compact 300W solution for Mini-ITX cases, while this Corsair model is a full-sized power supply. You should select this alternative if you need high wattage and modern ATX 3.0 features. It sacrifices the small footprint of the Apevia for much greater power capacity and standard form factor compatibility.
Corsair RM850x 850W Fully Modular ATX 3.1 PSU
This Corsair RM850x delivers 850W of power in a standard ATX form factor. It measures 2.3 x 3.39 x 5.91 inches and supports ATX 3.1 and PCIe 5.1 standards. The unit is fully modular and includes a 12V-2x6 connector for modern GPUs. It is designed for standard desktop builds rather than compact SFF cases. The Apevia unit is a compact 300W power supply for Mini-ITX systems. You should choose this Corsair model if you need more power and do not require a small form factor. It provides higher wattage and modern connectivity standards, making it suitable for high-performance desktops that fit in standard ATX cases.
Corsair RM750x Shift White 750W ATX Power Supply
The Corsair RM750x Shift offers 750W of power with a unique side-cable layout. It measures 6.3 x 5.91 x 3.39 inches and supports ATX 3.1 and PCIe 5.1 standards. This unit is fully modular and features 80 Plus Gold efficiency. It is designed for standard ATX cases with side-panel clearance. The Apevia unit is a compact 300W power supply for Mini-ITX systems. You should pick this alternative if you need more power and have a standard ATX case. It provides higher wattage and modern connectivity standards but requires more space than the tiny Apevia unit. It is not suitable for compact builds due to its size and power requirements.
Quick picks
Our 7 picks
Apevia 300W Mini-ITX Power Supply
Best for: compact Mini-ITX and 1U low-draw systems
- Wattage
- 300W
- Form Factor
- ATX
- Dimensions
- 5.91 × 1.59 × 3.21 inches
View on Amazon: Apevia 300W Mini-ITX Power Supply Affiliate link
The Apevia 300W Mini-ITX Power Supply delivers 300 watts of power designed for Mini-ITX, Flex-ATX, and 1U chassis. Measuring 5.91 by 3.21 by 1.59 inches, it includes a thermally controlled 40mm double ball-bearing fan and separable 20+4 pin motherboard and 4+4 pin CPU leads. This unit suits you if you need compact, low-draw power for home theater setups, small office servers, or legacy motherboard replacements.
Pros
- Compact dimensions fit 1U, Flex-ATX, and Mini-ITX chassis
- Separable 20+4 pin main and 4+4 pin CPU connectors
- 40mm double ball-bearing fan with thermal speed control
- Equipped with OVP, OCP, and SCP protection circuits
Cons
- Manual 115V/230V voltage switch required
- No PCIe connectors for dedicated graphics cards
- Limited to two SATA power connectors
Good fit if
- You need a compact power supply for a Mini-ITX, Flex-ATX, or 1U server chassis.
- You run low-draw hardware requiring up to 300 watts of total output.
- You need separable connectors to support both modern and legacy motherboards.
Skip if
- You need dedicated PCIe power cables for an add-in graphics card.
- You require automatic voltage switching rather than a manual toggle.
- You need to power more than two SATA storage drives.
Verdict: Apevia 300W Mini-ITX Power Supply delivers compact, reliable power for Mini-ITX and 1U systems that stay under 300 watts. Its separable connectors make it an adaptable choice for both modern and legacy low-draw builds.
MSI MAG 850W Fully Modular ATX Power Supply
Best for: modern ATX builds needing 850W Gold efficiency
- Wattage
- 850W
- Efficiency Rating
- 80+ Gold
- Modularity
- Fully Modular
- ATX Version
- ATX 3.1
- PCIe Connector Type
- 12V-2x6
- Warranty
- 10 Year
View on Amazon: MSI MAG 850W Fully Modular ATX Power Supply Affiliate link
The MSI 850W Gold Fully Modular Power Supply provides 850W of continuous power for gaming setups. It features an ATX 3.1 specification, PCIe 5.1 compatibility, and a dedicated 12V-2x6 connector. You get 80 Plus Gold efficiency and full modularity, allowing you to connect only the cables your build requires. It suits your system if you are moving from a low-wattage unit to a modern, high-draw graphics configuration.
Pros
- 80 Plus Gold efficiency rating
- Fully modular cable design
- ATX 3.1 and PCIe 5.1 ready with native 12V-2x6 connector
- 10-year warranty coverage
Cons
- Standard ATX form factor does not fit dedicated small-form-factor ITX slots
- Power output capped at 850W
Good fit if
- You need an ATX 3.1 power supply with a native 12V-2x6 connector.
- You want fully modular cabling backed by a 10-year warranty.
Skip if
- You require an ultra-compact ITX or SFX casing footprint.
- You need 1000W or higher power delivery for ultra-high-end hardware.
Verdict: MSI 850W Gold Fully Modular Power Supply delivers ATX 3.1 capability and 80 Plus Gold efficiency for modern hardware. It gives your system dependable 850W capacity with tidy, fully modular cabling.
Corsair RM850x Shift 850W White ATX Power Supply
Best for: Standard ATX builds needing 850W
- Wattage
- 850W
- Efficiency Rating
- 80 Plus Gold
- Modularity
- Fully Modular
- ATX Version
- ATX 3.1
- PCIe Connector Type
- PCIe 5.1
- Dimensions
- 6.3 × 5.91 × 3.39 inches
View on Amazon: Corsair RM850x Shift 850W White ATX Power Supply Affiliate link
This is a fully modular ATX power supply rated at 850W. It carries an 80 Plus Gold efficiency rating and supports ATX 3.1 standards with PCIe 5.1 connectors. The unit measures 6.3 inches in length and weighs 3.75 pounds. It is designed for users who need reliable high-wattage power for modern gaming rigs. The shift connector design helps manage cable routing in compact cases.
Pros
- 80 Plus Gold efficiency rating
- ATX 3.1 standard support
- PCIe 5.1 connector compatibility
- Fully modular cable design
Cons
- Heavier than many competitors at 3.75 pounds
- Larger footprint with 6.3 inch length
- No mention of zero-RPM fan mode in specs
Good fit if
- You need 850W of stable power
- You build with ATX 3.1 cases
- You use PCIe 5.1 GPUs
Skip if
- You require a compact ITX form factor
- You need a 300W unit
- You prefer a lighter power supply
Verdict: Corsair RM850x Shift 850W ATX 3.1 is a solid choice for builders who prioritize efficiency and modern connector standards over compact size. It fits well in standard ATX cases where space is not the primary constraint.
Corsair RM1000x 1000W ATX 3.1 PSU
Best for: high-power modern ATX desktop builds
- Wattage
- 1000W
- Efficiency Rating
- Cybenetics Gold
- Modularity
- Fully Modular
- ATX Version
- ATX 3.1
- PCIe Connector Type
- 12V-2x6
- PCIe Version
- PCIe 5.1
View on Amazon: Corsair RM1000x 1000W ATX 3.1 PSU Affiliate link
This Corsair unit is a 1000W ATX power supply designed for demanding systems. It provides full modularity, letting you attach only the cables you need. Built to the ATX 3.1 standard, it includes a dedicated 12V-2x6 connector with PCIe 5.1 support for modern graphics cards. It holds a Cybenetics Gold efficiency rating. If you need far more capacity than a basic 300W unit, this fits standard ATX cases with high power demands.
Pros
- 1000W power capacity
- ATX 3.1 and PCIe 5.1 compliant
- Includes 12V-2x6 connector
- Fully modular cable system
- Cybenetics Gold efficiency rating
Cons
- Standard ATX form factor does not fit dedicated ITX cases
- Heavier build at 6.88 pounds
Good fit if
- You need 1000W of power for high-draw components.
- You require native 12V-2x6 PCIe 5.1 connectivity.
- You want a fully modular power supply to minimize extra cables.
Skip if
- You are building inside a compact ITX-only enclosure.
- You only need low wattage for basic computing tasks.
Verdict: Corsair RMx Series 1000W ATX Power Supply delivers 1000W of fully modular power with modern ATX 3.1 and PCIe 5.1 connectivity. It is a capable upgrade when moving from lower-wattage units to a high-draw ATX setup.
Corsair RM1000x Shift 1000W Power Supply
Best for: high-draw systems needing ATX 3.0 side connections
- Wattage
- 1000W
- Efficiency Rating
- 80 Plus Gold
- Modularity
- Fully Modular
- ATX Version
- ATX 3.0
- Dimensions
- 7.09 × 5.91 × 5.08 inches
- Weight
- 4.2 pounds
View on Amazon: Corsair RM1000x Shift 1000W Power Supply Affiliate link
This is a 1000W ATX power supply featuring ATX 3.0 compliance, 80 Plus Gold efficiency, and full modularity. Unlike compact 300W ITX alternatives, it delivers high output with a modular side interface and PCIe 5.0 readiness. Its 7.09-inch length requires a standard ATX enclosure with side clearance. It suits you if you are building a high-draw desktop system and need high wattage paired with organized cable management.
Pros
- High 1000W continuous capacity with 80 Plus Gold efficiency
- Compliant with ATX 3.0 and PCIe 5.0 standards
- Fully modular connections with side-facing interface
Cons
- Large ATX form factor does not fit ITX cases
- Chassis length of 7.09 inches requires extra case depth
Good fit if
- You need 1000W of power for high-draw hardware
- You build in an ATX chassis that accommodates side-facing cables
Skip if
- You require a compact power supply for a Mini-ITX build
- You only need 300W for basic computing tasks
Verdict: Corsair RM1000x Shift 1000W ATX PSU provides high wattage and ATX 3.0 support for standard desktop cases.
Corsair RM850x 850W Fully Modular ATX 3.1 PSU
Best for: 850W builds requiring ATX 3.1 compliance
- Wattage
- 850W
- Efficiency Rating
- Cybenetics Gold
- Modularity
- Fully Modular
- ATX Version
- ATX 3.1
- PCIe Connector Type
- 12V-2x6
- PCIe Version
- PCIe 5.1
View on Amazon: Corsair RM850x 850W Fully Modular ATX 3.1 PSU Affiliate link
This ATX power supply delivers 850W of continuous power with Cybenetics Gold efficiency. It adheres to ATX 3.1 and PCIe 5.1 standards and features a dedicated 12V-2x6 connector for modern graphics cards. Fully modular cabling lets you attach only the leads you need. It suits you if you need reliable high wattage for a standard desktop case rather than a compact ITX enclosure.
Pros
- ATX 3.1 compliant with PCIe 5.1 support
- Dedicated 12V-2x6 power connector
- Cybenetics Gold efficiency certification
- Fully modular cable system
Cons
- Standard ATX form factor does not fit mini-ITX cases
- Weighs 3.9 pounds
Good fit if
- You build in a case that supports full-sized ATX power supplies.
- You use modern GPUs requiring a PCIe 5.1 12V-2x6 connector.
- You want fully modular cables to reduce case clutter.
Skip if
- You need a small ITX or Flex-ATX power supply.
- You require 1000W or higher capacity for heavier workloads.
Verdict: Corsair RM850x 850W ATX Power Supply delivers modern PCIe 5.1 and ATX 3.1 compatibility with 850W of fully modular power. It is an optimal choice if your case accepts full ATX units.
Corsair RM750x Shift White 750W ATX Power Supply
Best for: 750W PC builds with side cable clearance
- Wattage
- 750W
- Efficiency Rating
- 80 Plus Gold
- Modularity
- Fully Modular
- ATX Version
- ATX 3.1
- Fan Size
- 140mm
- PCIe Version
- PCIe 5.1
View on Amazon: Corsair RM750x Shift White 750W ATX Power Supply Affiliate link
The Corsair RM750x Shift is a 750-watt ATX power supply featuring 80 Plus Gold efficiency and ATX 3.1 compliance. Rather than placing modular connections on the rear, it positions them on the side with compact micro-fit cables. It suits you if you need PCIe 5.1 power support and Japanese 105°C capacitors in an ATX chassis that accommodates side-facing cables.
Pros
- Side-mounted modular interface simplifies cable routing
- ATX 3.1 and PCIe 5.1 certified for transient power handling
- 140mm fluid dynamic bearing fan with Zero RPM mode
- 100% Japanese 105°C-rated electrolytic capacitors
Cons
- Standard ATX casing does not fit compact ITX cases
- Side-facing modular plugs require clearance behind the PSU chamber
Good fit if
- You want ATX 3.1 compliance and PCIe 5.1 hardware support.
- You have an ATX case with side space to access the connection panel.
- You prefer compact micro-fit modular cables to reduce case clutter.
Skip if
- You are building inside a dedicated small-form-factor ITX enclosure.
- You require more than 750W of total power for high-draw hardware.
Verdict: Corsair RM750x Shift 750W ATX Power Supply provides 80 Plus Gold efficiency and ATX 3.1 capability using a unique side-cable layout. It is a dependable mid-wattage choice whenever your case provides the required side-panel clearance.
Specifications side by side
| Spec | Apevia 300W Mini-ITX Power Supply | MSI MAG 850W Fully Modular ATX Power Supply | Corsair RM850x Shift 850W White ATX Power Supply | Corsair RM1000x 1000W ATX 3.1 PSU | Corsair RM1000x Shift 1000W Power Supply | Corsair RM850x 850W Fully Modular ATX 3.1 PSU | Corsair RM750x Shift White 750W ATX Power Supply |
|---|---|---|---|---|---|---|---|
| Wattage | 300W | 850W | 850W | 1000W | 1000W | 850W | 750W |
| Efficiency Rating | not stated | 80+ Gold | 80 Plus Gold | Cybenetics Gold | 80 Plus Gold | Cybenetics Gold | 80 Plus Gold |
| Modularity | not stated | Fully Modular | Fully Modular | Fully Modular | Fully Modular | Fully Modular | Fully Modular |
| ATX Version | not stated | ATX 3.1 | ATX 3.1 | ATX 3.1 | ATX 3.0 | ATX 3.1 | ATX 3.1 |
| PCIe Connector Type | not stated | 12V-2x6 | PCIe 5.1 | 12V-2x6 | not stated | 12V-2x6 | not stated |
| Fan Size | not stated | not stated | not stated | not stated | not stated | not stated | 140mm |
| Warranty | not stated | 10 Year | not stated | not stated | not stated | not stated | not stated |
| Form Factor | ATX | Compact | ATX | ATX | ATX | ATX | ATX |
| PCIe Version | not stated | PCIe 5.1 | PCIe 5.1 | PCIe 5.1 | not stated | PCIe 5.1 | PCIe 5.1 |
| Recommended Use | not stated | Gaming | not stated | not stated | not stated | not stated | not stated |
| Connector | not stated | 12V-2x6 Connector | not stated | 12V-2x6 Connector | not stated | 12V-2x6 Connector | not stated |
| Size | not stated | 850W (PCIE 5) | 850W | 1000W | 1000W | 850W | 750W |
| Dimensions | 5.91 × 1.59 × 3.21 inches | 12 × 8.75 × 4.92 inches | 6.3 × 5.91 × 3.39 inches | 2.3 × 3.39 × 5.91 inches | 7.09 × 5.91 × 5.08 inches | 2.3 × 3.39 × 5.91 inches | 6.3 × 5.91 × 3.39 inches |
| Weight | not stated | not stated | 3.75 pounds | 6.88 pounds | 4.2 pounds | 3.9 pounds | 3.75 pounds |
| Model | ITX-AP300W | not stated | not stated | not stated | not stated | not stated | CP-9020273-NA |
| Color | not stated | not stated | White | Black | Black | Black | White |
If you need a different form factor for your build, see silverstone tek micro atx alternatives for comparable power ratings.
Frequently asked questions
Can these ATX power supplies fit in a Mini-ITX case?
No, standard ATX units are too large for Mini-ITX cases. The Apevia ITX-AP300W measures just 5.91 x 3.21 x 1.59 inches, fitting tight spaces. In contrast, alternatives like the MSI MAG 850W measure 12 x 8.75 x 4.92 inches. These larger units require standard ATX chassis with proper mounting points and airflow clearance.
Which alternative supports the latest PCIe 5.1 standard?
Several high-wattage options support PCIe 5.1 for modern GPUs. The MSI MAG 850W, Corsair RM850x Shift, Corsair RM1000x, Corsair RM850x, and Corsair RM750x Shift all feature PCIe 5.1 compatibility. They use the 12V-2x6 connector for direct GPU power. The original Apevia unit does not list this specific connector support in its specifications.
Do these alternatives offer fully modular cabling?
Yes, most listed alternatives provide fully modular cabling for easier installation. The MSI MAG 850W, Corsair RM850x Shift, Corsair RM1000x, Corsair RM1000x Shift, Corsair RM850x, and Corsair RM750x Shift are all fully modular. This allows you to connect only the cables you need, reducing clutter. The Apevia ITX-AP300W uses separable connectors for adaptability in small builds.
What is the difference between ATX 3.0 and ATX 3.1?
ATX 3.1 is the newer standard supporting higher peak power and PCIe 5.1. The Corsair RM1000x Shift is listed as ATX 3.0 compliant. Most other alternatives, including the MSI MAG 850W and Corsair RM850x Shift, support ATX 3.1. This ensures compatibility with the latest graphics cards and power delivery requirements for modern systems.
Are there white-colored options available for these builds?
Yes, white finishes are available for specific high-wattage models. The Corsair RM850x Shift and Corsair RM750x Shift both come in white. These units maintain 80 Plus Gold efficiency and ATX 3.1 compliance. The other alternatives, such as the MSI MAG 850W and Corsair RM1000x, are listed in black. Choose based on your case color scheme.
Which PSU is best for a 1000W high-draw system?
For 1000W needs, the Corsair RM1000x and Corsair RM1000x Shift are top choices. Both deliver 1000W of fully modular power with ATX 3.1 or 3.0 support. The RM1000x Shift includes side cable clearance design. These units replace lower-wattage options when upgrading to high-performance components that require significant power headroom.
Does the Apevia unit have an efficiency rating listed?
The provided data for the Apevia ITX-AP300W does not list an 80 Plus efficiency rating. It focuses on compact dimensions and 300W output. In contrast, most alternatives specify their efficiency. The MSI MAG 850W, Corsair RM850x Shift, Corsair RM750x Shift, and Corsair RM1000x Shift all hold 80 Plus Gold certification for better energy efficiency.
How do the dimensions of the Corsair Shift series compare?
The Corsair Shift series features a unique side-cable layout that affects dimensions. The RM850x Shift measures 6.3 x 5.91 x 3.39 inches. The RM750x Shift shares these exact dimensions. The standard Corsair RM1000x is thinner at 2.3 inches long but wider. These differences impact cable routing and case compatibility for your specific build.