15 Best ATX PC Power Supplies, Compared
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Choosing the right ATX PC power supply ensures your system receives stable electricity while supporting your hardware requirements. The MSI MAG 850W Fully Modular ATX Power Supply leads the list because it combines ATX 3.1 compliance, a native 12V-2x6 connector, and 80 Plus Gold efficiency with a 10-year warranty.
We evaluated 15 products strictly using the specifications published on their official listings. This guide helps you determine the right wattage, modular cabling layout, and connector standards for your build.
Quick picks
The best fit for you
- You build a modern ATX 3.1 gaming PC MSI MAG 850W Fully Modular ATX Power Supply It provides 850W output, ATX 3.1 compliance, native PCIe 5.1 cabling, and a 10-year warranty.
- You run high-draw hardware requiring 1000W of power Corsair RM1000x 1000W ATX 3.1 PSU It supplies 1000W capacity alongside native ATX 3.1 and PCIe 5.1 support.
- You build an all-white rig needing side connectors Corsair RM850x Shift 850W White ATX Power Supply Its white casing and side-facing modular connectors simplify cable access in cases with side clearance.
- You want a basic 700W unit for simple builds Thermaltake Smart 700W 80 Plus White PSU It delivers continuous 700W power with 80 Plus White efficiency and Active PFC.
Our 15 picks
MSI MAG 850W Fully Modular ATX Power Supply
Best for: modern 850W ATX 3.1 gaming builds
- Form Factor
- ATX
- Wattage
- 850W
- Efficiency Rating
- 80+ Gold
- Modularity
- Fully Modular
- ATX Version
- ATX 3.1
- PCIe Connector Type
- 12V-2x6
View on Amazon: MSI MAG 850W Fully Modular ATX Power Supply (paid link)
This MSI unit is an 850W ATX power supply built for gaming rigs. It features the ATX 3.1 specification and PCIe 5.1 readiness, complete with a native 12V-2x6 connector. The fully modular cable setup ensures you only plug in what your build requires. An 80 Plus Gold efficiency rating manages power draw, and a 10-year warranty covers the hardware. It suits you if you need current standards.
Pros
- ATX 3.1 and PCIe 5.1 compliance
- Native 12V-2x6 connector
- 80 Plus Gold efficiency rating
- Fully modular cable design
- 10-year warranty
Cons
- 850W maximum output limits headroom for higher-draw systems
- Efficiency rated at Gold rather than Platinum or Titanium
- No passive or zero-RPM fan mode listed in specs
Good fit if
- You need an ATX 3.1 power supply with a 12V-2x6 connector.
- You want fully modular cables to reduce case clutter.
- You run an 850W gaming setup and require a 10-year warranty.
Skip if
- You need 1000W or more for high-draw hardware.
- You require an 80 Plus Platinum or Titanium efficiency rating.
Verdict: MSI MAG 850W Fully Modular ATX PSU delivers ATX 3.1 power and PCIe 5.1 connectivity with 80 Plus Gold efficiency. It provides long-term coverage via a 10-year warranty for modern mid-to-high-tier gaming PCs.
Corsair RM850x 850W Fully Modular ATX 3.1 PSU
Best for: modern ATX builds needing 850W capacity
- Form Factor
- ATX
- Wattage
- 850W
- Efficiency Rating
- Cybenetics Gold
- Modularity
- Fully Modular
- ATX Version
- ATX 3.1
- PCIe Connector Type
- 12V-2x6
View on Amazon: Corsair RM850x 850W Fully Modular ATX 3.1 PSU (paid link)
This Corsair unit is an 850W ATX power supply designed for modern desktop builds. It features ATX 3.1 compliance and PCIe 5.1 support to handle current hardware demands. You get a fully modular setup that lets you attach only the cables you need. The inclusion of a dedicated 12V-2x6 connector supports newer graphics hardware directly. It suits you if you want an 850W black power supply for an updated ATX configuration.
Pros
- 850W power output
- Fully modular cabling
- Complies with ATX 3.1 and PCIe 5.1 standards
- Equipped with a 12V-2x6 connector
Cons
- 850W capacity limits headroom for systems needing 1000W or more
- Standard ATX size will not fit dedicated SFX cases
Good fit if
- You need an 850W power supply that meets ATX 3.1 specifications.
- You want a fully modular design to keep extra cables out of your case.
- You use components that require a native 12V-2x6 power connector.
Skip if
- You require 1000W or higher output for higher-draw hardware.
- You are building inside a compact small-form-factor case requiring an SFX unit.
Verdict: Corsair RM850x 850W ATX Power Supply provides 850W of fully modular power with updated ATX 3.1 and PCIe 5.1 standards. It delivers a solid power foundation with an included 12V-2x6 connector for modern ATX systems.
Corsair RM1000x 1000W ATX 3.1 PSU
Best for: modern ATX 3.1 high-wattage builds
- Form Factor
- ATX
- Wattage
- 1000W
- Efficiency Rating
- Cybenetics Gold
- Modularity
- Fully Modular
- ATX Version
- ATX 3.1
- PCIe Connector Type
- 12V-2x6
View on Amazon: Corsair RM1000x 1000W ATX 3.1 PSU (paid link)
This is a 1000W ATX power supply built for high-demand systems. It features full modularity, allowing you to attach only the cables you need. Built to ATX 3.1 standards, it includes PCIe 5.1 support and a dedicated 12V-2x6 connector for modern graphics cards. At 6.88 pounds and standard ATX dimensions, this unit suits you if you need clean cable management, modern connector standards, and high capacity.
Pros
- 1000W continuous power delivery
- Fully modular cable design
- ATX 3.1 and PCIe 5.1 compliant
- Dedicated 12V-2x6 connector included
Cons
- Relatively heavy at 6.88 pounds
- Offered only in black finish
Good fit if
- You require 1000W of power for high-draw PC components.
- You need native ATX 3.1 and PCIe 5.1 connectivity with a 12V-2x6 port.
- You want fully modular cables to simplify routing inside your case.
Skip if
- You need a lightweight power supply under 6.88 pounds.
- You require a white power supply to match your build theme.
Verdict: Corsair 1000W Modular ATX Power Supply provides 1000W output with full modularity and native PCIe 5.1 support. It fits modern builds requiring ATX 3.1 compliance.
Corsair RM1000e 1000W ATX Power Supply
Best for: high-wattage PC builds needing modular cabling
- Form Factor
- ATX
- Wattage
- 1000 Watt
- Efficiency Rating
- 80 PLUS Gold
- Modularity
- Fully Modular
- Size
- 1000W
- Dimensions
- 5.91 × 5.51 × 3.39 inches
View on Amazon: Corsair RM1000e 1000W ATX Power Supply (paid link)
The Corsair RM1000e is an ATX power supply built for high-demand computer builds. It delivers up to 1000 watts of continuous power with an 80 Plus Gold efficiency rating. The fully modular design lets you attach only the cables your setup requires, keeping your case organized. Dual EPS12V connectors provide dedicated motherboard power. This unit suits you if you need reliable, high-wattage delivery for demanding multi-component hardware configurations.
Pros
- 1000-watt power capacity
- 80 Plus Gold efficiency rating
- Fully modular cable design
- Dual EPS12V motherboard connectors
- 105°C-rated internal capacitors
Cons
- Efficiency capped at 80 Plus Gold rather than Platinum
- Chassis finish limited to black
Good fit if
- You need 1000 watts of output for power-heavy components.
- You want fully modular cabling to reduce clutter inside your case.
- You require dual EPS12V connections for your motherboard.
Skip if
- You require an efficiency rating above 80 Plus Gold.
- You need a white enclosure for a color-matched PC build.
Verdict: Corsair RM1000e 1000W ATX Power Supply delivers robust output and modular cable management for high-draw PCs. It provides reliable 80 Plus Gold efficiency alongside dual EPS12V connectivity for demanding hardware setups.
Corsair RM1000x Shift 1000W Power Supply
Best for: high-power ATX 3.0 builds with side clearance
- Form Factor
- ATX
- Wattage
- 1000W
- Efficiency Rating
- 80 Plus Gold
- Modularity
- Fully Modular
- ATX Version
- ATX 3.0
- Dimensions
- 7.09 × 5.91 × 5.08 inches
View on Amazon: Corsair RM1000x Shift 1000W Power Supply (paid link)
This ATX power supply provides 1000W of continuous output with an 80 Plus Gold efficiency rating. It features a fully modular side interface with ATX 3.0 and PCIe 5.0 compliance. At 7.09 inches long, the unit connects power cables via the side rather than the rear. You get dedicated high-wattage delivery suited for hardware setups requiring clean cable routing and modern power standards.
Pros
- 1000W power capacity
- 80 Plus Gold efficiency rating
- Fully modular side interface
- ATX 3.0 and PCIe 5.0 compliant
Cons
- 7.09-inch length requires clearance in smaller cases
- Side-mounted interface requires lateral chassis space
Good fit if
- You need 1000W of fully modular power.
- You build with ATX 3.0 and PCIe 5.0 hardware.
- You have a PC case with space for side-mounted connectors.
Skip if
- You use a compact case unable to accommodate a 7.09-inch chassis.
- You lack side clearance for the modular side interface.
Verdict: Mkastry 1000W RM1000x Shift ATX Power Supply delivers 1000W with 80 Plus Gold efficiency and an ATX 3.0 modular side interface. It serves high-draw systems in cases designed with adequate lateral connector clearance.
Corsair RM850x Shift 850W White ATX Power Supply
Best for: white ATX builds needing side cable access
- Form Factor
- ATX
- Wattage
- 850W
- Efficiency Rating
- 80 Plus Gold
- Modularity
- Fully Modular
- ATX Version
- ATX 3.1
- PCIe Connector Type
- PCIe 5.1
View on Amazon: Corsair RM850x Shift 850W White ATX Power Supply (paid link)
The Corsair RM850x Shift is an 850-watt ATX power supply featuring a white finish and fully modular design with side-mounted connections. Built to ATX 3.1 and PCIe 5.1 standards, it delivers modern hardware support with 80 Plus Gold efficiency and a Zero RPM cooling profile. You will appreciate this unit if you want clean cable management in a compatible ATX case and need reliable 850W power for your modern build.
Pros
- Certified 80 Plus Gold efficiency
- Complies with ATX 3.1 and PCIe 5.1 specifications
- Fully modular system with side-facing cable connectors
- Zero RPM fan mode for low-load operation
Cons
- Side-facing connectors require a chassis with clearance beside the power supply bay
- Length of 6.3 inches may restrict space in compact ATX cases
Good fit if
- You want an 850W supply compliant with ATX 3.1 and PCIe 5.1 standards.
- You are assembling a white-themed system in a chassis designed for side-cable access.
Skip if
- You have a PC chassis without side clearance behind the power supply bay.
- You need more than 850W for higher-draw workstation components.
Verdict: Corsair RM850x Shift 850W White Power Supply delivers current ATX 3.1 and PCIe 5.1 compliance with 80 Plus Gold efficiency. Its side-facing modular connectors simplify cable access if your case provides adequate side clearance.
MSI MAG ATX 3.0 Modular Power Supply
Best for: ATX 3.0 gaming rigs using renewed hardware
- Form Factor
- ATX
- Efficiency Rating
- 80 Plus Gold
- Modularity
- Full Modular
- ATX Version
- ATX 3.0
- PCIe Connector Type
- PCIe 5.0
- Fan Size
- 120mm
View on Amazon: MSI MAG ATX 3.0 Modular Power Supply (paid link)
This renewed unit is a fully modular ATX power supply built for modern gaming setups. It features ATX 3.0 compatibility and includes a native PCIe 5.0 connector designed to support graphics cards such as the RTX 40 series. Rated for 80 Plus Gold efficiency, it uses an LLC full bridge topology with a DC-DC module and active PFC. It suits you if you need modern connector support in a standard ATX build.
Pros
- 80 Plus Gold efficiency certification
- Native PCIe 5.0 connector with ATX 3.0 compatibility
- Fully modular flat cable setup
- 120mm fluid dynamic bearing cooling fan
- Built-in OVP, OCP, OPP, OTP, SCP, and UVP protections
Cons
- Supplied as a renewed product
- Supports ATX 3.0 rather than the newer ATX 3.1 specification
Good fit if
- You run an Nvidia RTX 40 series graphics card that uses a native PCIe 5.0 connector.
- You want fully modular flat cables to keep ATX case wiring tidy.
- You target an 80 Plus Gold efficiency level.
Skip if
- You prefer factory-new hardware over a renewed unit.
- You require compliance with the newer ATX 3.1 standard.
Verdict: MSI MAG ATX 3.0 Modular Power Supply delivers 80 Plus Gold efficiency and native PCIe 5.0 connectivity in a renewed ATX form factor.
Corsair RM750x Shift White 750W ATX Power Supply
Best for: modern 750W builds requiring side cable access
- Form Factor
- ATX
- Wattage
- 750W
- Efficiency Rating
- 80 Plus Gold
- Modularity
- Fully Modular
- ATX Version
- ATX 3.1
- Fan Size
- 140mm
View on Amazon: Corsair RM750x Shift White 750W ATX Power Supply (paid link)
The Corsair RM750x Shift is a 750W fully modular ATX power supply featuring side-mounted cable connections. It complies with ATX 3.1 and PCIe 5.1 standards to handle transient power spikes from modern hardware. The unit includes an 80 Plus Gold efficiency rating and a 140mm fluid dynamic bearing fan. This power supply suits you if your PC case provides enough clearance next to the side panel for modular Type 5 cable access.
Pros
- Intel ATX 3.1 certified with PCIe 5.1 support
- Side-mounted modular panel for direct cable access
- 80 Plus Gold certified efficiency
- 140mm fluid dynamic bearing cooling fan
- 100% 105°C-rated Japanese electrolytic capacitors
Cons
- 750W maximum output provides less headroom than higher-wattage models
- Side-facing connections require dedicated clearance beside the power supply bay
Good fit if
- You want an ATX 3.1 power supply with side-facing modular connectors.
- You need 750W of continuous power with 80 Plus Gold efficiency.
- You use a PC chassis with adequate side-panel space for Type 5 micro-fit cables.
Skip if
- You require more than 750W of total output for high-draw hardware configurations.
- You build in an enclosure that lacks clearance alongside the PSU connector block.
Verdict: Corsair RM750x Shift 750W ATX Power Supply delivers ATX 3.1 compliance and 80 Plus Gold efficiency through a side-facing modular layout. It provides reliable power delivery for compatible PC cases designed with adequate side clearance.
NZXT 12VHPWR to Dual 8-Pin PCIe Adapter Cable
Best for: NZXT C-Series Gold power supply owners
- Form Factor
- ATX
- Weight
- 6 ounces
View on Amazon: NZXT 12VHPWR to Dual 8-Pin PCIe Adapter Cable (paid link)
This is a dedicated 12VHPWR adapter cable designed to connect an existing ATX 2.X power supply directly to an NVIDIA 40 Series graphics card. It delivers up to 600 watts through a 12+4-pin connector powered by dual 8-pin PCIe ports. If you already own an NZXT C-Series Gold power supply, you can power modern graphics cards without replacing your entire unit for an ATX 3.0 model.
Pros
- Delivers up to 600 watts of power
- Connects dual 8-pin PSU ports to a 12+4-pin 12VHPWR connector
- Enables NVIDIA 40 Series GPU use on ATX 2.X units without ATX 3.0
- Replaces bulky standard GPU adapters
Cons
- Adapter cable only, not a standalone power supply
- Guaranteed compatibility limited to NZXT C-Series Gold ATX 2.X power supplies
Good fit if
- You run an NZXT C-Series Gold ATX 2.X power supply.
- You need to power an NVIDIA 40 Series graphics card up to 600 watts.
- You want a direct cable replacement for the standard adapter.
Skip if
- You need a complete standalone ATX power supply unit.
- You use a power supply from a different brand or model series.
Verdict: NZXT 12VHPWR PCIe Adapter Cable provides a direct 600-watt connection between an NVIDIA 40 Series graphics card and supported NZXT C-Series Gold units. It lets you upgrade your GPU without replacing your ATX 2.X power supply.
OwlTree 8-Pin to Dual 8-Pin PCIe Cable
Best for: Corsair modular PSU owners powering graphics cards
- Form Factor
- ATX
View on Amazon: OwlTree 8-Pin to Dual 8-Pin PCIe Cable (paid link)
This adapter cable provides an ATX 8-pin power supply connection splitting into two 6+2-pin PCIe outputs. It uses 18AWG tinned copper wiring measuring 75 centimeters in total, split into 60-centimeter and 15-centimeter segments. You get dual GPU power connectors from a single modular port. It suits you if you own a compatible Corsair modular unit and need extra PCIe power connectors for your graphics card without replacing your entire power supply.
Pros
- Dual 6+2-pin PCIe connectors fit 6-pin or 8-pin GPU sockets
- Constructed with 18AWG tinned copper wiring
- Total length of 75 cm provides 60 cm plus 15 cm reach
- Compatible across Corsair RM, RMX, HX, and other modular lines
Cons
- Restricted exclusively to specified Corsair modular power supplies
- PSU 8-pin end cannot be swapped with the PCIe ends
- Only provides a single cable without additional power connectors
Good fit if
- You own a compatible Corsair modular PSU and need another GPU connection.
- You require up to 75 centimeters of cable length for your graphics card.
Skip if
- You operate a non-Corsair power supply unit.
- You need a complete power supply unit rather than an accessory cable.
Verdict: OwlTree 8-Pin to Dual 6+2-Pin PCIe Cable delivers dual GPU power feeds from a single Corsair modular PSU port using 18AWG wiring. It expands connector availability for compatible hardware setups without replacing the power supply.
Thermaltake Toughpower Grand 850W Gold PSU
Best for: Continuous high-temperature ATX system operation
- Form Factor
- ATX
- Wattage
- 850W
- Efficiency Rating
- 80 PLUS Gold
- Modularity
- Fully Modular
- ATX Version
- ATX 12V 2.3
- Fan Size
- 14cm
View on Amazon: Thermaltake Toughpower Grand 850W Gold PSU (paid link)
The Thermaltake Toughpower Grand 850W Modular PSU is a fully modular ATX power supply built for sustained operation. It delivers 850 watts of continuous power at 50°C and holds an 80 Plus Gold efficiency certification. A 140mm dual ball bearing fan handles internal cooling, supported by Japanese 105°C capacitors. This unit suits you if you need reliable continuous delivery for demanding ATX workloads.
Pros
- 80 Plus Gold certified efficiency from 87% to 93%
- 850W continuous output rated at 50°C
- Fully modular cable configuration
- 100% Japanese 105°C electrolytic and solid-state capacitors
Cons
- Follows older Intel ATX 12V 2.3 standard
- Lacks native 12VHPWR or PCIe 5.0 cabling
Good fit if
- You need guaranteed 850W continuous output in high-temperature environments.
- You want fully modular cabling with all-Japanese 105°C capacitors.
- You run standard ATX hardware without PCIe 5.0 power requirements.
Skip if
- You need modern ATX 3.0 or ATX 3.1 power specifications.
- You require a native 16-pin 12VHPWR cable for your graphics card.
Verdict: Thermaltake Toughpower Grand 850W Modular PSU delivers reliable continuous power at 50°C with high-grade internal components. It provides dependable Gold-rated efficiency for builds using conventional ATX power connectors.
Optimal Shop 20+4 Pin LCD Power Supply Tester
Best for: troubleshooting ATX power supplies and cables
- Form Factor
- ATX
- Display Type
- LCD Display
- Dimensions
- 8.3 × 3.7 × 0.8 inches
- Weight
- 3.2 ounces
View on Amazon: Optimal Shop 20+4 Pin LCD Power Supply Tester (paid link)
This is an 8-in-1 power supply diagnostic tester housed in an aluminum alloy shell rather than a full power supply. It features a 1.8-inch LCD screen to check voltage outputs across 20-pin, 24-pin, SATA, PCIe, and IDE connectors. A built-in buzzer alarm notifies you if the Power Good signal fails. It suits you if you need to verify voltages or troubleshoot existing ATX units safely before building your PC.
Pros
- 1.8-inch LCD screen displays output voltages directly
- Buzzer alarm sounds when the power supply PG signal fails
- Supports 20-pin, 24-pin, SATA, PCIe 6-pin, and 4-pin/8-pin connectors
- Aluminum alloy shell weighs 0.2 pounds
Cons
- Diagnostic tool only and does not deliver system power
- LCD screen requires a connected 20-pin or 24-pin connector to operate
Good fit if
- You need to verify rail voltages across standard ATX and peripheral connectors.
- You want an audible alert for failed PG signals during power testing.
Skip if
- You need an actual power supply unit to operate a PC.
- You require native support for 16-pin 12VHPWR cables.
Verdict: Optimal Shop LCD Power Supply Tester provides a dedicated diagnostic readout with a 1.8-inch screen and buzzer alarm for multi-connector ATX setups. It helps you quickly verify voltage rails and identify failing power units before assembling hardware.
Thermaltake Blue Sleeved 20+4-Pin ATX Cable
Best for: blue ATX motherboard cable routing
- Form Factor
- ATX
- Dimensions
- 19.7 × 15 × 6.3 inches
- Weight
- 6.35 ounces
View on Amazon: Thermaltake Blue Sleeved 20+4-Pin ATX Cable (paid link)
This item is an individually sleeved 20+4-pin ATX cable from Thermaltake in blue. It features a 20+4-pin ATX connection, measures 19.68 inches long, and weighs 0.39 pounds. You can use it to connect your motherboard to a power supply unit. It suits you if you want a dedicated blue motherboard lead for an ATX build.
Pros
- Individually sleeved blue cable wires
- Standard 20+4-pin ATX motherboard connector
- Cable length of 19.68 inches
Cons
- Only a single cable rather than a complete power supply
- Only includes the 20+4-pin main motherboard lead
Good fit if
- You need a blue individually sleeved 20+4-pin ATX cable.
- You want a motherboard power lead measuring 19.68 inches.
Skip if
- You need an entire ATX power supply unit.
- You prefer a color other than blue.
Verdict: Thermaltake Individually Sleeved 20+4Pin ATX Cable is a standalone blue 20+4-pin motherboard wire for ATX systems. It suits builders seeking a 19.68-inch individually sleeved cable instead of standard bundled wiring.
Optimal Shop LCD ATX Power Supply Tester
Best for: testing ATX power supply voltage rails
- Form Factor
- ATX
- Display Type
- LCD Display
View on Amazon: Optimal Shop LCD ATX Power Supply Tester (paid link)
This unit is an aluminum diagnostic tester rather than a power supply. It reads rail voltages across 20-pin and 24-pin ATX plugs on a 1.8-inch LCD screen. It also tests SATA, floppy, and PCIe connections, and includes a buzzer alarm for Power Good signal failures. You get a portable tool to check output voltages before connecting components to your system.
Pros
- 1.8-inch LCD screen displays output voltage readouts
- Audible buzzer alarm alerts to Power Good value faults
- Tests 20-pin, 24-pin, SATA, PCIe, and peripheral connectors
- Aluminum alloy casing for heat dissipation and durability
Cons
- Diagnostic tool only, provides no system operating power
- Requires main 20-pin or 24-pin connection to power the LCD display
Good fit if
- You need to verify ATX, SATA, and PCIe rail voltages before assembling a PC.
- You want an audible alert if a power supply fails its Power Good check.
Skip if
- You need an actual power supply to run computer hardware.
- You require testing for 16-pin 12VHPWR or PCIe 5.0 cables.
Verdict: Optimal Shop LCD ATX Power Supply Tester is a dedicated diagnostic tool for checking rail outputs and Power Good signals. Its 1.8-inch display and buzzer provide clear operational warnings across multiple common connector types.
Thermaltake Smart 700W 80 Plus White PSU
Best for: entry-level 80 Plus White ATX builds
- Form Factor
- ATX
- Wattage
- 700W
- Efficiency Rating
- 80+ White
- ATX Version
- ATX 12V V2.3
- Fan Size
- 120mm
- Warranty
- 5 Year
View on Amazon: Thermaltake Smart 700W 80 Plus White PSU (paid link)
The Thermaltake Smart 700W 80 Plus White PSU delivers up to 700W of continuous power for standard ATX computer cases. It features an 80 Plus White efficiency rating reaching up to 86 percent, Active PFC, and ATX 12V V2.3 compliance. Cooling is handled by an integrated 120mm fan. If you need a straightforward power supply backed by a 5-year warranty for a basic desktop build, this unit covers your core requirements.
Pros
- 700W continuous power delivery
- 80 Plus White certified with efficiency up to 86%
- Active Power Factor Correction
- 5-year manufacturer warranty
Cons
- Lower electrical efficiency compared to 80 Plus Bronze or Gold units
- Built to the older ATX 12V V2.3 standard
Good fit if
- You need 700W of continuous power for an ATX chassis.
- You want an entry-level power supply backed by a 5-year warranty.
Skip if
- You require high-efficiency certifications such as 80 Plus Gold.
- You need modern power delivery standards like ATX 3.0 or PCIe 5.0.
Verdict: Thermaltake Smart 700W 80 Plus White PSU delivers continuous 700W power and Active PFC backed by a 5-year warranty. It serves standard ATX builds that do not require higher efficiency ratings.
Specifications side by side
| Spec | MSI MAG 850W Fully Modular ATX Power Supply | Corsair RM850x 850W Fully Modular ATX 3.1 PSU | Corsair RM1000x 1000W ATX 3.1 PSU | Corsair RM1000e 1000W ATX Power Supply | Corsair RM1000x Shift 1000W Power Supply | Corsair RM850x Shift 850W White ATX Power Supply | MSI MAG ATX 3.0 Modular Power Supply | Corsair RM750x Shift White 750W ATX Power Supply | NZXT 12VHPWR to Dual 8-Pin PCIe Adapter Cable | OwlTree 8-Pin to Dual 8-Pin PCIe Cable | Thermaltake Toughpower Grand 850W Gold PSU | Optimal Shop 20+4 Pin LCD Power Supply Tester | Thermaltake Blue Sleeved 20+4-Pin ATX Cable | Optimal Shop LCD ATX Power Supply Tester | Thermaltake Smart 700W 80 Plus White PSU |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Wattage | 850W | 850W | 1000W | 1000 Watt | 1000W | 850W | not specified | 750W | not specified | not specified | 850W | not specified | not specified | not specified | 700W |
| Efficiency Rating | 80+ Gold | Cybenetics Gold | Cybenetics Gold | 80 PLUS Gold | 80 Plus Gold | 80 Plus Gold | 80 Plus Gold | 80 Plus Gold | not specified | not specified | 80 PLUS Gold | not specified | not specified | not specified | 80+ White |
| Modularity | Fully Modular | Fully Modular | Fully Modular | Fully Modular | Fully Modular | Fully Modular | Full Modular | Fully Modular | not specified | not specified | Fully Modular | not specified | not specified | not specified | not specified |
| ATX Version | ATX 3.1 | ATX 3.1 | ATX 3.1 | not specified | ATX 3.0 | ATX 3.1 | ATX 3.0 | ATX 3.1 | not specified | not specified | ATX 12V 2.3 | not specified | not specified | not specified | ATX 12V V2.3 |
| PCIe Connector Type | 12V-2x6 | 12V-2x6 | 12V-2x6 | not specified | not specified | PCIe 5.1 | PCIe 5.0 | not specified | not specified | not specified | not specified | not specified | not specified | not specified | not specified |
| Fan Size | not specified | not specified | not specified | not specified | not specified | not specified | 120mm | 140mm | not specified | not specified | 14cm | not specified | not specified | not specified | 120mm |
| Warranty | 10 Year | not specified | not specified | not specified | not specified | not specified | not specified | not specified | not specified | not specified | not specified | not specified | not specified | not specified | 5 Year |
| Form Factor | ATX | ATX | ATX | ATX | ATX | ATX | ATX | ATX | ATX | ATX | ATX | ATX | ATX | ATX | ATX |
| PCIe Version | PCIe 5.1 | PCIe 5.1 | PCIe 5.1 | not specified | not specified | PCIe 5.1 | not specified | PCIe 5.1 | not specified | not specified | not specified | not specified | not specified | not specified | not specified |
| Recommended Use | Gaming | not specified | not specified | not specified | not specified | not specified | Gaming | not specified | not specified | not specified | not specified | not specified | not specified | not specified | not specified |
| Connector | 12V-2x6 Connector | 12V-2x6 Connector | 12V-2x6 Connector | not specified | not specified | not specified | not specified | not specified | not specified | not specified | not specified | not specified | not specified | not specified | not specified |
| Power Factor Correction | not specified | not specified | not specified | not specified | not specified | not specified | not specified | not specified | not specified | not specified | not specified | not specified | not specified | not specified | Active PFC |
| Size | 850W (PCIE 5) | 850W | 1000W | 1000W | 1000W | 850W | not specified | 750W | not specified | 75 centimeters | 850W | not specified | not specified | not specified | 700W |
| Display Type | not specified | not specified | not specified | not specified | not specified | not specified | not specified | not specified | not specified | not specified | not specified | LCD Display | not specified | LCD Display | not specified |
| Dimensions | 12 × 8.75 × 4.92 inches | 2.3 × 3.39 × 5.91 inches | 2.3 × 3.39 × 5.91 inches | 5.91 × 5.51 × 3.39 inches | 7.09 × 5.91 × 5.08 inches | 6.3 × 5.91 × 3.39 inches | 11.8 × 7.9 × 3.9 inches | 6.3 × 5.91 × 3.39 inches | not specified | not specified | 13.3 × 8.27 × 6.18 inches | 8.3 × 3.7 × 0.8 inches | 19.7 × 15 × 6.3 inches | not specified | 5.9 × 5.8 × 3.5 inches |
| Weight | not specified | 3.9 pounds | 6.88 pounds | 3.66 pounds | 4.2 pounds | 3.75 pounds | 3.97 pounds | 3.75 pounds | 6 ounces | not specified | 6 pounds | 3.2 ounces | 6.35 ounces | not specified | 2.2 pounds |
| Color | not specified | Black | Black | Black | Black | White | not specified | White | Black | Black | not specified | Black | Blue | Golden | Black |
| Model | not specified | not specified | not specified | not specified | not specified | not specified | not specified | CP-9020273-NA | PA-xG1BB | OT-CS-ADP-001 | PS-TPG-0850MPCGUS-1 | Optimal Shop | AC-009-CN5NAN-PB | Optimal Shop | SPD-0700NP |
Is an ATX Power Supply Worth It?
ATX power supplies provide standardized mounting for mid-tower and full-tower computer chassis. Choosing an ATX form factor ensures your power supply fits standard case compartments and aligns with 20+4-pin motherboard layouts. However, physical dimensions vary substantially among ATX units. Depths range from under 6 inches to over 13 inches, affecting bottom-shroud cable clearance. Models featuring side-facing modular interfaces also demand extra lateral room between the chassis side panel and the power supply frame. Standard ATX dimensions simplify component layout when your case provides sufficient internal clearance.
Worth it if
- You assemble hardware inside a standard PC case engineered for an ATX power supply.
- You select a side-connecting model and your chassis provides adequate lateral clearance.
Skip it if
- You build inside a compact enclosure that cannot clear power supply depths exceeding 11 inches.
- You purchase a side-facing modular unit but your chassis lacks lateral connector clearance.
When you select an ATX power supply, ensure dimensions fit your chosen PC case with RGB for proper clearance and airflow.
How We Chose ATX Supplies
To assemble this guide to the 15 options, we identified models on Amazon that specifically state the ATX form factor in their title or feature list. We include only one size or variant per product family. Every detail comes directly from published manufacturer specifications, without physical testing or handling.
The list arranges products in stock first, then by Amazon sales rank, placing better-selling products first. You can compare these units using published specifications such as wattage output, modular cabling design, 80 Plus efficiency, and compliance with ATX 3.1 or PCIe 5.1 standards.
Key Specifications for Choosing an ATX PSU
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Select System Wattage Capacity
Calculate total component power draw before purchasing. ATX power supplies range from 700W up to 1000W output. Choose 700W or 750W units for basic gaming builds. Select 850W or 1000W units for demanding multi-component hardware configurations. The Corsair RM1000e 1000W ATX Power Supply delivers 1000W capacity for high-draw PCs requiring dual EPS12V connectivity. Always inspect manufacturer hardware specifications for minimum recommended wattage. Insufficient continuous wattage causes instability during peak power consumption. Verify your graphics card and processor power requirements first. Match PSU capacity directly to total hardware demand.
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Compare 80 Plus Efficiency Ratings
Review efficiency ratings to determine electrical loss. Standard ratings include 80 Plus White and 80 Plus Gold. Higher efficiency ratings waste less electricity as heat during power conversion. The Thermaltake Smart 700W 80 Plus White PSU provides basic 80 Plus White efficiency with Active PFC. Select 80 Plus Gold units if you operate your system under continuous heavy workloads. Gold-certified models run cooler and convert alternating current to direct current more effectively. Check the published efficiency specification on the product label. Confirm the rating aligns with your intended thermal targets and daily operational hours.
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Evaluate Cable Modularity Design
Examine cable modularity before building. Fully modular designs feature fully detachable wiring harnesses. Non-modular power supplies retain fixed wiring bundles. The MSI MAG 850W Fully Modular ATX Power Supply uses a fully modular setup. You connect only required cables to maintain unobstructed interior airflow. This flexibility simplifies cable routing inside compact chassis compartments. Non-modular units force you to stow unused wiring inside the chassis basement. Select fully modular units when building in cases where space is limited. Verify which modular cable harnesses come packaged in the box before installation.
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Check Lateral Connector Orientation
Check modular connector placement on the power supply casing. Standard ATX power supplies place modular sockets on the back face. Specialized units place connections on the side panel. The Corsair RM850x Shift 850W White ATX Power Supply uses side-facing modular connectors. This layout eases cable plugging inside cases with open side clearance. However, side-facing sockets require adequate clearance between the power unit and the chassis side panel. Measure your case compartment dimensions carefully before choosing side-panel designs. Standard rear-facing connections fit conventional cases lacking specialized lateral cable channel cutouts.
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Assess Thermal Operating Ratings
Inspect rated operating temperatures for continuous electrical output. Heavy system loads raise internal chassis ambient temperatures quickly. Entry-level units often drop stability at high ambient heat levels. The Thermaltake Toughpower Grand 850W Gold PSU guarantees continuous power output at 50°C. High temperature ratings indicate internal component quality capable of enduring warm environments. Check thermal specifications if your PC operates in confined spaces or runs sustained computing jobs. Confirm your case fans provide sufficient intake airflow toward the power supply. Robust operating temperature tolerances prevent unexpected shutdowns under extreme continuous thermal stress.
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Test Voltage Rails Pre-Assembly
Diagnose power delivery before attaching sensitive motherboard components. Hardware faults risk damaging expensive parts during initial startup. Standalone diagnostic devices let you bench-test units before installation. The Optimal Shop 20+4 Pin LCD Power Supply Tester displays live voltage rail readings on a 1.8-inch screen. Built-in buzzer alarms immediately sound if voltages drop out of tolerance or Power Good signals fail. You can quickly detect defective wiring or failing rails using dedicated diagnostic equipment. Test your power supply pins before cable routing inside your PC chassis. Early voltage verification prevents hardware damage and troubleshooting delays.
Frequently asked questions
What is the difference between ATX 3.0 and ATX 3.1 power supplies?
ATX 3.1 updates the high-power GPU connector standard from 12VHPWR to the revised 12V-2x6 specification. This design shortens the sensing pins and deepens power pins to ensure secure seating before power flows. Units like the Corsair RM850x and MSI MAG 850W include native 12V-2x6 connections, whereas ATX 3.0 units rely on earlier 12VHPWR implementations.
What are side-facing modular connectors on an ATX power supply?
Side-facing modular connections place cable ports on the PSU side rather than the back face. Corsair RM850x Shift and RM750x Shift utilize this layout to ease cable plug-in access behind motherboard trays. You must verify that your chassis provides adequate lateral clearance between the power supply compartment and the side panel before choosing one.
Can you use an older ATX power supply with a modern PCIe 5.0 graphics card?
Yes, you can power PCIe 5.0 GPUs with older ATX units using dedicated adapter cables. For example, the NZXT adapter converts dual standard 8-pin PSU outputs into a 600W connector for supported NZXT C-Series Gold power supplies. This setup supplies necessary graphics card wattage without requiring a full power supply replacement.
What is the purpose of an LCD ATX power supply tester?
An LCD tester checks whether an ATX power supply outputs proper rail voltages before you connect computer components. Tools like the Optimal Shop tester use a 1.8-inch screen and audible buzzers to identify irregular voltages or missing Power Good signals. This diagnostic step prevents potential damage to motherboards and graphics cards caused by malfunctioning power hardware.
What is the difference between 80 Plus White and 80 Plus Gold ratings?
Efficiency ratings indicate how effectively a power supply converts wall AC current into DC power without wasting energy as heat. An 80 Plus White unit, such as the Thermaltake Smart 700W, offers baseline 80 percent efficiency under typical loads. An 80 Plus Gold model reaches higher efficiency thresholds, resulting in cooler internal temperatures and lower electrical draw.
How does operating temperature affect an ATX power supply?
High operating temperatures can degrade component efficiency and reduce continuous wattage output if internal parts overheat. Heavy-duty power supplies, such as the Thermaltake Toughpower Grand 850W, are engineered to maintain their full rated output continuously at temperatures up to 50°C. Robust thermal tolerance prevents unexpected shutdowns when you operate demanding systems inside compact or restricted-airflow PC cases.
What does Active PFC do in a power supply?
Active Power Factor Correction aligns voltage and current waveforms to maximize electrical efficiency from your wall outlet. Power supplies like the Thermaltake Smart 700W include Active PFC to reduce harmonic distortion and avoid wasted electricity. This feature stabilizes total power transmission, ensuring your computer receives uniform electrical energy while conforming to standard electrical guidelines.