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Black rectangular ATX power supply with 140 mm fan and modular cable sockets

Corsair

Corsair RM850x CP-9020270-NA power supply

SKU CH-B3Z7-BC957 MPN CP-9020270-NA

Fully modular 850 W ATX 3.1 power supply with Cybenetics Gold efficiency, 12V-2x6 connector, Japanese 105°C capacitors and a 140 mm fan

  • Max wattage850 W
  • Modular cablingFull Modular
  • Fan configuration1 × 140 mm
  • Main power connector24Pin
  • PSU length limit160 mm
  • Efficiency certificationCybenetics Gold

Model ATX 3.1 80+ Gold (850W)

  • Fully modular design lets you use only the cables you need
  • Cybenetics Gold certification confirms high energy efficiency
  • ATX 3.1 compliance and PCIe 5.1 support ready for modern hardware
  • Native 12V-2x6 connector provides direct GPU power
  • 100 % Japanese 105 °C capacitors ensure long-term reliability

Fully modular 850 W ATX 3.1 supply

The Corsair RM850x delivers 850 W through a fully modular design that lets builders connect only the cables they need. It meets the ATX 3.1 specification and includes a native 12V-2x6 connector for modern graphics cards. Cybenetics Gold certification confirms high efficiency across typical loads. Ultra-flexible embossed cables with low-profile combs simplify routing in compact cases.

Build integration and cable freedom

A single 140 mm fan handles cooling while a rear knob adjusts the fan curve for quieter operation. The 160 mm chassis depth fits standard ATX layouts and leaves room for cable management behind the motherboard tray. Full modularity removes unused power leads, freeing space for airflow and custom sleeving. Japanese 105 °C-rated electrolytic capacitors support long-term reliability.

Thermals, noise and power draw

The unit accepts 100-240 V input at 47-63 Hz for worldwide compatibility. Under normal loads the fan remains near idle speeds, keeping acoustic output low. Cybenetics Gold efficiency reduces waste heat, so the PSU draws less from the wall for a given system demand. The 12V rail supplies up to 70 A to power high-end GPUs and CPUs without strain.

How it compares

Measured against everything we stock in ATX Desktop Power Supplies, at today’s prices. Recalculated every night.

Price $120.99
Cheaper than about 58% of the 10,869 comparable items (median $142.99).
Max wattage 850 W
Typical for this category: the median of 930 items is 850 W.

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Specifications

Product
Brand nameCORSAIR
Product lineRMx Series
Model nameRM850x
Part numberCP-9020270-NA
Product colorBlack
Product typeATX 3.1 Compatible
Ports & slots
Connection types1 × 12VHPWR (12+4) PCIe / 1 × 24 pin ATX / 2 × 8 pin (4+4) EPS (CPU) / 3 × 8 pin (6+2) PCIe / 3 x PATA / 8 x SATA
Power
Max wattage850 W
Modular cablingFull Modular
Main power connector24Pin
Efficiency certificationCybenetics Gold
Supply voltage100–240 V
AC input frequency47–63 Hz
Rated input current+3.3 V@20A, +5 V@20A, +5Vsb@3A
Size & build
Shipping weight3.43 kg
Package size305 × 216 × 130 mm
Compatibility
PSU length limit160 mm
In the box
Included itemsRM850x Power Supply | DC Cable Kit | Power Cord | Mounting Screws | Cable Ties
More details
Fan configuration1 × 140 mm

Other versions of this model

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Questions about this item

How much continuous output can the 850 W unit deliver before its protection circuits engage?

The power supply is rated for 850 W maximum power, so sustained loads at or above that level will trigger over-power protection and shut the unit down.

What is the fan behaviour and thermal profile when the PSU runs at high load for hours?

A single 140 mm fan operates with a speed-adjustment knob; at high load it spins faster to move more air, and the 105 °C-rated Japanese capacitors are specified to handle the resulting internal temperatures.

Which cables must already be in the case for the RM850x to connect to the motherboard and drives?

The PSU includes a 24-pin ATX cable, two 8-pin EPS cables, three 8-pin PCIe cables, one 12+4-pin PCIe cable, SATA cables and PATA cables; no additional cables are required for standard motherboards and drives.

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