ATX 3.1 or ATX 3.0 PC Power Supplies? Compared by Specs
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When you compare an atx 31 vs atx 30 PC power supply, you look at how each unit handles modern components. Both the MSI MAG 850W and the Corsair RM1000x Shift offer 80 Plus Gold efficiency and fully modular designs. The main difference lies in their power output and physical footprint. One provides higher wattage in a smaller case, while the other offers a standard ATX 3.1 framework with more raw power for demanding builds.
Key differences
| Aspect | MSI MAG 850W Fully Modular ATX Power Supply | Corsair RM1000x Shift 1000W Power Supply |
|---|---|---|
| Wattage | 850W | 1000W |
| ATX Version | ATX 3.1 | ATX 3.0 |
| PCIe Version | PCIe 5.1 | PCIe 5.0 |
| Width | 8.75 inches | 5.91 inches |
| Warranty | 10 Year | not listed |
Which one should you choose?
Choose MSI MAG 850W Fully Modular ATX Power Supply if
- You need the latest ATX 3.1 standard with PCIe 5.1 support for future-proofing your GPU connections.
- You want a longer 10-year warranty coverage for peace of mind.
- You are building a standard ATX case where the larger 8.75-inch width fits comfortably.
Choose Corsair RM1000x Shift 1000W Power Supply if
- You require 1000W of power to support high-end graphics cards under heavy load.
- You have a small form factor or SFX case that requires a narrower 5.91-inch width.
- You prefer the established ATX 3.0 and PCIe 5.0 compliance for current generation hardware.
Verdict: Choose the MSI MAG 850W if you prioritize the newer ATX 3.1 specification and a longer warranty. Pick the Corsair RM1000x Shift if your system demands 1000W or if your case requires a narrower power supply profile.
ATX 3.1 vs ATX 3.0 PSU Specs
atx version
The MSI MAG uses the newer ATX 3.1 standard, while the Corsair RM1000x Shift adheres to ATX 3.0. This difference matters for future-proofing your build. ATX 3.1 offers updated guidelines for power delivery and transient response. You get better support for the latest hardware requirements with the MSI unit. The Corsair model remains compliant with the previous generation, which is still robust for current GPUs. If you want the most recent specification support, the MSI MAG has the clear advantage here. It aligns with the latest industry updates for power supply design.
pcie version
Connector technology is critical for high-end graphics cards. The MSI MAG supports PCIe 5.1, ensuring compatibility with the newest GPU power standards. It uses a 12V-2x6 connector for these connections. The Corsair RM1000x Shift supports PCIe 5.0. While PCIe 5.0 is fully capable of handling current flagship cards, the MSI unit offers a slight edge in versioning. This means the MSI is ready for any upcoming revisions to the PCIe power specification. You benefit from the newer standard if you plan to upgrade to the very latest hardware in the near future.
wattage
Power output is a key deciding factor for system stability. The Corsair RM1000x Shift provides 1000W of continuous power. The MSI MAG offers 850W. If your system includes a high-end CPU and a power-hungry GPU, the Corsair unit gives you more headroom. This extra wattage ensures the power supply does not run at maximum capacity under heavy loads. The MSI 850W is sufficient for many gaming rigs, but the Corsair provides more margin for extreme configurations. You should choose the Corsair if you need that extra power reserve.
efficiency rating
Both power supplies achieve an 80 Plus Gold efficiency rating. This means they convert at least 87% of AC power to DC power at typical loads. Neither unit has an advantage in this category. You will see similar energy savings and heat generation from both models. The efficiency rating indicates how much electricity is wasted as heat. Since both are Gold rated, they perform equally well in terms of power conversion. This is a tie, as the data shows identical ratings for both the MSI and Corsair models.
dimensions
Physical size affects compatibility with your case. The Corsair RM1000x Shift is significantly more compact. It measures 7.09 inches in length, 5.91 inches in width, and 5.08 inches in height. The MSI MAG is much larger, measuring 12 inches in length, 8.75 inches in width, and 4.92 inches in height. The Corsair unit fits into smaller cases more easily. The MSI unit requires a case with ample space for a long power supply. If you are building in a compact chassis, the Corsair is the better choice due to its smaller footprint.
Which PSU matches your build needs
Users wanting latest ATX 3.1 standard
The MSI MAG A850GL supports the newer ATX 3.1 specification. This version provides updated guidelines for power delivery and transient response. You get PCIe 5.1 readiness with a 12V-2x6 connector. The 10-year warranty offers long-term security. This unit is ideal if you prioritize the most current technical standards for your gaming rig.
Builders needing high wattage output
The Corsair RM1000x Shift delivers 1000W of power. This higher wattage provides more headroom for extreme components. It is fully modular and meets ATX 3.0 compliance. The compact side-interface design simplifies cable management. If your system requires more power than 850W, this unit offers the necessary capacity for high-end builds.
Those prioritizing compact physical dimensions
The Corsair RM1000x Shift measures 5.91 inches in width and 7.09 inches in length. This small footprint fits easily into smaller cases. In contrast, the MSI MAG is significantly larger at 12 inches long. If space is limited in your chassis, the Corsair design provides a better fit without sacrificing efficiency or modularity.
Quick picks
| # | Product | Best for | Price |
|---|---|---|---|
| 1 | MSI MAG 850W Fully Modular ATX Power Supply | Modern gaming PCs needing ATX 3.1 | Check price of MSI MAG 850W Fully Modular ATX Power Supply on Amazon |
| 2 | Corsair RM1000x Shift 1000W Power Supply | ATX 3.0 builds with side-mount cable needs | Check price of Corsair RM1000x Shift 1000W Power Supply on Amazon |
The products compared
MSI MAG 850W Fully Modular ATX Power Supply
Best for: Modern gaming PCs needing ATX 3.1
- ATX Version
- ATX 3.1 (what this guide is about)
- Wattage
- 850W
- Efficiency Rating
- 80+ Gold
- Modularity
- Fully Modular
- PCIe Connector Type
- 12V-2x6
- Warranty
- 10 Year
View on Amazon: MSI MAG 850W Fully Modular ATX Power Supply Affiliate link
This is an 850W fully modular power supply built for modern gaming rigs. It supports ATX 3.1 and PCIe 5.1 standards, ensuring compatibility with the latest graphics cards. The unit features an 80 Plus Gold efficiency rating and includes a 12V-2x6 connector. Its compact dimensions make it suitable for smaller cases. You get a 10-year warranty for long-term reliability.
Pros
- ATX 3.1 standard support
- 80 Plus Gold efficiency
- Fully modular cable management
- 10-year warranty coverage
Cons
- 850W output may limit high-end builds
- No mention of cable length details
- Compact size may restrict airflow in tight cases
Good fit if
- You need ATX 3.1 compatibility
- You want a fully modular design
- You prefer an 80 Plus Gold rating
Skip if
- You require higher than 850W power
- You need non-ATX 3.1 specific features
- You prefer a non-modular unit
Verdict: MSI MAG A850GL 850W ATX 3.1 fits users needing modern ATX 3.1 support and efficient power delivery for gaming systems within its wattage range.
Corsair RM1000x Shift 1000W Power Supply
Best for: ATX 3.0 builds with side-mount cable needs
- ATX Version
- ATX 3.0 (what this guide is about)
- Wattage
- 1000W
- Efficiency Rating
- 80 Plus Gold
- Modularity
- Fully Modular
- Dimensions
- 7.09 × 5.91 × 5.08 inches
- Weight
- 4.2 pounds
View on Amazon: Corsair RM1000x Shift 1000W Power Supply Affiliate link
This Corsair unit delivers 1000W of power with ATX 3.0 compliance and 80 Plus Gold efficiency. Its side-mount modular interface helps manage cables in compact cases. The 5.91 x 5.08 x 7.09 inch chassis fits standard ATX enclosures. You should choose this if you need high wattage for modern GPUs while keeping cable clutter low.
Pros
- 1000W output for high-end builds
- ATX 3.0 and PCIe 5.0 compliant
- 80 Plus Gold efficiency rating
- Side-mount modular interface
Cons
- ATX 3.0 standard instead of newer ATX 3.1
- Heavier at 4.2 pounds
- Standard ATX dimensions may not fit smallest cases
Good fit if
- You need ATX 3.0 compliance for PCIe 5.0
- You want 1000W for high-end GPUs
- You prefer side-mount cable management
Skip if
- You require the latest ATX 3.1 standard
- You need a smaller form factor than ATX
- You prioritize ultra-compact dimensions over wattage
Verdict: Corsair RM1000x Shift 1000W ATX 3.0 suits builders needing ATX 3.0 compliance and side-mount cable management for high-end GPUs.
Specifications side by side
| Spec | MSI MAG 850W Fully Modular ATX Power Supply | Corsair RM1000x Shift 1000W Power Supply |
|---|---|---|
| Wattage | 850W | 1000W |
| Efficiency Rating | 80+ Gold | 80 Plus Gold |
| Modularity | Fully Modular | Fully Modular |
| ATX Version | ATX 3.1 | ATX 3.0 |
| PCIe Connector Type | 12V-2x6 | not stated |
| Warranty | 10 Year | not stated |
| Form Factor | Compact | ATX |
| PCIe Version | PCIe 5.1 | not stated |
| Recommended Use | Gaming | not stated |
| Connector | 12V-2x6 Connector | not stated |
| Size | 850W (PCIE 5) | 1000W |
| Dimensions | 12 × 8.75 × 4.92 inches | 7.09 × 5.91 × 5.08 inches |
| Weight | not stated | 4.2 pounds |
| Color | not stated | Black |
Frequently asked questions
Does ATX 3.1 support the latest GPU connectors?
Yes, ATX 3.1 includes support for the 12V-2x6 connector. This standard ensures compatibility with modern graphics cards that require high power delivery. You can rely on this specification for new builds. The MSI MAG 850W unit uses this connector, making it ready for current hardware trends.
What is the main difference between ATX 3.0 and 3.1?
The primary difference is the version standard each unit follows. ATX 3.1 offers updated guidelines for power delivery and transient response compared to ATX 3.0. This makes newer standards better for future-proofing. You should choose ATX 3.1 if you want the most recent technical specifications for your system.
Are these power supplies fully modular?
Yes, both listed models are fully modular. This means you can connect only the cables you need, reducing clutter inside your case. The MSI MAG and Corsair RM1000x Shift both feature this design. It helps with cable management and improves airflow within your PC chassis.
Is ATX 3.0 still good for high-end builds?
Yes, ATX 3.0 remains a solid choice for high-end builds. The Corsair RM1000x Shift operates at this standard and provides 1000W of power. It is suitable for builders needing side-mount cable management. You get reliable performance without needing the absolute newest ATX 3.1 features.
Which PSU is better for gaming PCs?
The MSI MAG 850W is recommended for modern gaming PCs. It supports the ATX 3.1 standard and includes a 12V-2x6 connector. This setup handles the power demands of current GPUs efficiently. You get PCIe 5.1 readiness, which is ideal for gamers who want to upgrade their graphics hardware later.
Do I need ATX 3.1 for my current GPU?
You may not strictly need ATX 3.1 if your current hardware does not require it. However, ATX 3.1 ensures you are ready for future components. The MSI MAG offers this newer standard. If you plan to upgrade soon, the newer version provides better long-term compatibility with latest graphics cards.