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- Best overall: Corsair RM850x (2024) 850W Fully Modular ATX Power Supply
- Best budget: Corsair RM750x (2024) 750W Fully Modular ATX Power Supply
- Best premium: Seasonic FOCUS GX-1000 ATX 3.1 Fully Modular Power Supply
- Best Seasonic alternative: Seasonic FOCUS GX-850 ATX 3.1 Fully Modular Power Supply
- Corsair RM850x (2024) and Seasonic FOCUS GX-850 ATX 3.1 both offer 850W, 80 PLUS Gold efficiency and fully modular cabling.
- Corsair RM850x (2024) stands out for its 140mm fan and ATX 3.1 support.
- Seasonic FOCUS GX-850 ATX 3.1 is a strong alternative with a 135mm fan and a 10-year warranty.
- Choose a 750W model for many midrange builds; step up to 1000W for more headroom.
Corsair RM850x (2024) and Seasonic FOCUS GX-850 ATX 3.1 are two strong 850W choices for a gaming or creator PC, with fully modular cables, 80 PLUS Gold efficiency and support for current graphics-card power connections. Corsair’s 140mm fan and Seasonic’s 135mm fan are useful points of comparison, but the best fit also depends on your case, GPU and preferred cable setup.
For this Black Friday 2026 buying guide, I researched and compared specs, reviews and owner feedback across seven fully modular power supplies. My pick for most people is Corsair RM850x (2024), while Seasonic FOCUS GX-850 ATX 3.1 is a close alternative. The guide also covers lower-wattage and higher-capacity options, plus practical checks to make before choosing a PSU.
How We Picked
- Compared rated wattage, efficiency certification, connector standards and fan size using manufacturer specifications.
- Prioritized fully modular designs that make cable routing and PC building easier.
- Reviewed owner feedback and product documentation for compatibility, noise and warranty details.
- Included 750W, 850W and 1000W options to suit different graphics cards and upgrade plans.
- Selected models with clear, identifiable product variants so buyers can compare like with like.
Comparison Table
| Product | Best for | Rated output | Efficiency | Standard |
|---|---|---|---|---|
| Corsair RM850x (2024) 850W Fully Modular ATX Power Supply | Most 850W gaming builds | 850W | 80 PLUS Gold | ATX 3.1 |
| Seasonic FOCUS GX-850 ATX 3.1 Fully Modular Power Supply | A Corsair alternative | 850W | 80 PLUS Gold | ATX 3.1 |
| Corsair RM750x (2024) 750W Fully Modular ATX Power Supply | Midrange graphics cards | 750W | 80 PLUS Gold | ATX 3.1 |
| Seasonic FOCUS GX-1000 ATX 3.1 Fully Modular Power Supply | Power-hungry upgrades | 1000W | 80 PLUS Gold | ATX 3.1 |
| be quiet! Pure Power 12 M 850W ATX 3.0 Power Supply | Noise-conscious PC builds | 850W | 80 PLUS Gold | ATX 3.0 |
| MSI MAG A850GL PCIE5 850W 80 PLUS Gold Power Supply | Compact 850W builds | 850W | 80 PLUS Gold | ATX 3.0 |
| Thermaltake Toughpower GF A3 850W 80 PLUS Gold Fully Modular Power Supply | Standard 850W gaming PCs | 850W | 80 PLUS Gold | ATX 3.0 |
Best Picks Reviewed
#1 · Top pick
Corsair RM850x (2024) 850W Fully Modular ATX Power Supply
The Corsair RM850x (2024) 850W Fully Modular ATX Power Supply is the best overall choice for most gaming PCs, pairing 850W output with an ATX 3.1 design.
Best for: Most 850W gaming builds
- Rated output
- 850W
- Efficiency
- 80 PLUS Gold
- Fan size
- 140mm
- Warranty
- 10 years
- ATX 3.1 and PCIe 5.1 support
- Fully modular cable connections
- Large 140mm fan
- An 850W unit is more capacity than basic office PCs need
Is the Corsair RM850x (2024) worth buying on Black Friday 2026?
Yes. Corsair RM850x (2024) 850W Fully Modular ATX Power Supply is a compelling pick for a modern gaming PC, with ATX 3.1 support, 850W capacity, Gold efficiency and a 10-year warranty.
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#2
Seasonic FOCUS GX-850 ATX 3.1 Fully Modular Power Supply
The Seasonic FOCUS GX-850 ATX 3.1 Fully Modular Power Supply is the best Corsair alternative for buyers who want 850W and a compact 135mm fan.
Best for: A Corsair alternative
- Rated output
- 850W
- Efficiency
- 80 PLUS Gold
- Fan size
- 135mm
- Warranty
- 10 years
- ATX 3.1 and PCIe 5.1 support
- Fully modular design
- 10-year warranty
- Fan is smaller than the Corsair RM850x fan
Is the Seasonic FOCUS GX-850 ATX 3.1 worth buying on Black Friday 2026?
Yes. Seasonic FOCUS GX-850 ATX 3.1 Fully Modular Power Supply suits a high-performance PC that needs 850W, Gold efficiency and a current GPU power connection. The Seasonic FOCUS GX-850 ATX 3.1 Fully Modular Power Supply's fully modular layout also helps keep unused cables out of the case.
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#3
Corsair RM750x (2024) 750W Fully Modular ATX Power Supply
The Corsair RM750x (2024) 750W Fully Modular ATX Power Supply is the best lower-capacity pick for midrange gaming PCs, with 750W output and ATX 3.1 support.
Best for: Midrange graphics cards
- Rated output
- 750W
- Efficiency
- 80 PLUS Gold
- Fan size
- 140mm
- Warranty
- 10 years
- ATX 3.1 and PCIe 5.1 support
- Fully modular cables
- Same 140mm fan size as the RM850x
- Less upgrade headroom than an 850W model
Is the Corsair RM750x (2024) worth buying on Black Friday 2026?
Yes. Corsair RM750x (2024) 750W Fully Modular ATX Power Supply is a sensible fit for a midrange gaming system that does not need 850W. The Corsair RM750x (2024) 750W Fully Modular ATX Power Supply's ATX 3.1 design, Gold rating and 10-year warranty make it a well-equipped lower-capacity option.
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#4
Seasonic FOCUS GX-1000 ATX 3.1 Fully Modular Power Supply
The Seasonic FOCUS GX-1000 ATX 3.1 Fully Modular Power Supply is the best high-capacity pick for demanding upgrades, delivering 1000W with Gold efficiency.
Best for: Power-hungry upgrades
- Rated output
- 1000W
- Efficiency
- 80 PLUS Gold
- Fan size
- 135mm
- Warranty
- 10 years
- 1000W capacity for demanding builds
- ATX 3.1 and PCIe 5.1 support
- Fully modular cables
- More capacity than most midrange systems require
Is the Seasonic FOCUS GX-1000 ATX 3.1 worth buying on Black Friday 2026?
Yes. Seasonic FOCUS GX-1000 ATX 3.1 Fully Modular Power Supply is a strong choice for a high-end system that needs 1000W and current GPU connectivity. Buyers with a modest graphics card can choose a lower-wattage model instead.
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#5
be quiet! Pure Power 12 M 850W ATX 3.0 Power Supply
The be quiet! Pure Power 12 M 850W ATX 3.0 Power Supply is the best quiet-focused alternative for an 850W build, with 80 PLUS Gold efficiency.
Best for: Noise-conscious PC builds
- Rated output
- 850W
- Efficiency
- 80 PLUS Gold
- Fan size
- 120mm
- Warranty
- 10 years
- ATX 3.0 and PCIe 5.0 support
- Fully modular cable design
- Designed for quiet operation
- Uses ATX 3.0 rather than ATX 3.1
Is the be quiet! Pure Power 12 M 850W worth buying on Black Friday 2026?
Yes. be quiet! Pure Power 12 M 850W ATX 3.0 Power Supply is a practical 850W option for builders prioritizing quiet operation. The be quiet! Pure Power 12 M 850W ATX 3.0 Power Supply has Gold efficiency, modular cables and PCIe 5.0 support, though its standard is ATX 3.0.
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#6
MSI MAG A850GL PCIE5 850W 80 PLUS Gold Power Supply
The MSI MAG A850GL PCIE5 850W 80 PLUS Gold Power Supply is the best compact-cable option for an 850W gaming build, with a 135mm fan.
Best for: Compact 850W builds
- Rated output
- 850W
- Efficiency
- 80 PLUS Gold
- Fan size
- 135mm
- Standard
- ATX 3.0
- Fully modular design
- Includes PCIe 5.0 GPU power support
- Compact power-supply body
- ATX 3.0 instead of ATX 3.1
Is the MSI MAG A850GL PCIE5 worth buying on Black Friday 2026?
Yes. MSI MAG A850GL PCIE5 850W 80 PLUS Gold Power Supply is worth considering for a space-conscious gaming PC that needs modular cabling and PCIe 5.0 GPU support. Check the case’s PSU length limit and the graphics card’s power requirements before choosing it.
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#7
Thermaltake Toughpower GF A3 850W 80 PLUS Gold Fully Modular Power Supply
The Thermaltake Toughpower GF A3 850W 80 PLUS Gold Fully Modular Power Supply is the best straightforward ATX 3.0 option for a standard 850W build.
Best for: Standard 850W gaming PCs
- Rated output
- 850W
- Efficiency
- 80 PLUS Gold
- Fan size
- 140mm
- Standard
- ATX 3.0
- Fully modular connections
- PCIe 5.0 GPU power support
- 140mm cooling fan
- Uses ATX 3.0 rather than ATX 3.1
Is the Thermaltake Toughpower GF A3 850W worth buying on Black Friday 2026?
Yes. Thermaltake Toughpower GF A3 850W 80 PLUS Gold Fully Modular Power Supply is a capable match for an 850W gaming PC, offering modular cables and PCIe 5.0 support. Compare its case fit and connector needs with the newer ATX 3.1 options.
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Which is better, Corsair RM850x or Seasonic FOCUS GX-850?
Corsair RM850x (2024) and Seasonic FOCUS GX-850 ATX 3.1 both deliver 850W, Gold efficiency and fully modular cabling. Corsair RM850x (2024) has a 140mm fan; Seasonic FOCUS GX-850 ATX 3.1 has a 135mm fan. Both models carry a 10-year warranty and support ATX 3.1.
The practical difference comes down to your preference for brand, cooling design and cable layout rather than a large capacity gap. Check the exact model name on the listing: older variants can have different standards or included GPU cables. For a modern build with a current graphics card, either option provides a strong foundation, provided the connectors match the card.
Is 850W enough for a gaming PC in 2026?
An 850W power supply is a strong match for many gaming PCs with a modern graphics card and a mainstream desktop processor. Corsair RM850x (2024) 850W Fully Modular ATX Power Supply and Seasonic FOCUS GX-850 ATX 3.1 Fully Modular Power Supply both offer that rated output.
Use the graphics-card maker’s recommended PSU capacity as your first check, then account for the processor, drives, fans and planned upgrades. A 750W unit serves many midrange systems, while a high-end GPU or substantial upgrade plan supports choosing a 1000W model. Leave comfortable capacity headroom rather than selecting by wattage alone.
What does ATX 3.1 mean for a power supply?
ATX 3.1 identifies a newer power-supply standard, and Corsair RM850x (2024) 850W Fully Modular ATX Power Supply and Seasonic FOCUS GX-850 ATX 3.1 Fully Modular Power Supply both use it. Each supports PCIe 5.1 graphics-card power connections.
The standard is a useful compatibility signal, not a substitute for checking the exact cable supplied with a PSU. Confirm that the graphics card’s power input matches the included connection and follow the card and PSU instructions. ATX 3.0 models in this guide still support PCIe 5.0 GPU connections, offering another route for compatible builds.
Should I choose 750W, 850W or 1000W?
Choose 750W for a midrange build, 850W for a broad range of gaming PCs, and 1000W for a high-capacity system or a planned upgrade. Corsair RM750x (2024) provides 750W, while Corsair RM850x (2024) and Seasonic FOCUS GX-850 each provide 850W.
Seasonic FOCUS GX-1000 ATX 3.1 is the 1000W option here. Skip it if your components do not need its capacity: extra wattage alone does not improve performance. Compare the GPU maker’s recommendation, processor demand and PSU dimensions before deciding. The right wattage keeps the system supplied without paying for capacity your build will not use.
What should I check before buying a PSU on Black Friday 2026?
Before choosing any power supply on Black Friday 2026, confirm its exact model, wattage, connectors, dimensions and warranty. Corsair RM850x (2024) and Seasonic FOCUS GX-850 ATX 3.1 each offer 850W, but other models in the same family have different capacities and standards.
Check your case’s PSU clearance and the GPU’s required power plug, then verify that the listing names the same variant as the product you want. Fully modular cables simplify routing, but cables are not interchangeable across every PSU model. Keep the original cables for that specific power supply and follow its installation guide.
Buying Guide
Match wattage to your graphics card
Use your GPU maker’s PSU recommendation as a starting point, then include the processor and other components. Corsair RM750x (2024) suits many midrange PCs; 850W models cover a wider range of gaming builds, and Seasonic FOCUS GX-1000 ATX 3.1 gives demanding systems 1000W.
Check the GPU power connector
Confirm the PSU includes the connection required by your exact graphics card. ATX 3.1 models in this guide support PCIe 5.1, while ATX 3.0 options support PCIe 5.0. Read the product specifications and card instructions before installation.
Measure the case clearance
Look up your case’s maximum PSU length and compare it with the dimensions for the exact unit. A modular PSU still needs room for the housing and cable bends. Check clearance around nearby drive cages and confirm the case supports the unit’s form factor.
Understand modular cabling
Fully modular designs let you connect only the cables your build needs, which helps with routing and unused cable storage. Use only cables supplied for that exact PSU model. Connector shapes that appear similar do not guarantee compatible wiring.
Compare warranty and product variant
Read the warranty terms for the exact model and confirm the listing’s wattage and ATX generation. Corsair RM850x (2024) and Seasonic FOCUS GX-850 ATX 3.1 each list a 10-year warranty. Check the included cables and model label before completing a purchase.
FAQ
Corsair RM850x vs Seasonic Focus: which is better for Black Friday 2026?
Corsair RM850x (2024) and Seasonic FOCUS GX-850 ATX 3.1 are both strong 850W choices with Gold efficiency, modular cables and ATX 3.1 support. Choose between them based on the exact cable setup, fan design, case fit and warranty details you prefer.
Is 850W enough for an RTX gaming PC?
An 850W unit is suitable for many RTX gaming PCs, but the exact graphics-card model matters. Corsair RM850x (2024) provides 850W and ATX 3.1 support. Check the GPU maker’s recommended PSU capacity and connector requirements before choosing a power supply.
Does Seasonic FOCUS GX-850 ATX 3.1 include PCIe 5.1 support?
Yes. Seasonic FOCUS GX-850 ATX 3.1 Fully Modular Power Supply supports PCIe 5.1 graphics-card power connections and offers 850W output. Confirm that the exact listing includes the cable your GPU requires, then follow the PSU and graphics-card installation instructions.
Is a 1000W power supply better than an 850W PSU?
A 1000W PSU is better for a system whose components or upgrade plans need that extra capacity; it is not automatically better for every PC. Seasonic FOCUS GX-1000 ATX 3.1 delivers 1000W, while many gaming builds work well with 850W.
Can I reuse modular PSU cables when replacing my power supply?
Do not assume modular cables are interchangeable, even when plugs appear to fit. Use only the cables supplied with the exact replacement power supply. Corsair RM850x (2024) and Seasonic FOCUS GX-850 ATX 3.1 have their own cable sets; check manufacturer documentation before reusing any cable.