We take cryptocurrency — so the coins you hold can buy real hardware.Pay in crypto, spend it on real hardware. Free insured shipping worldwide over $399. Plain, unbranded boxes, sent from Germany.Free insured shipping over $399. Your rate is locked for 30 minutes once checkout opens.Rate locked 30 minutes. Every item sealed, serial-checked and covered by a 24-month warranty.Sealed, 24-month warranty.

Saved items Sign in
Black rectangular ATX power supply unit with ventilation grille and cable bundle

Cooler Master

Cooler Master Elite RS400-PSARJ3-US 400W ATX power supply

SKU CH-B5V5-1ZD56

A 400 W ATX power supply compliant with ATX 12V V2.3, delivering over 70 % efficiency at typical load with dual +12 V rails and multiple protection circuits

  • TypeAT
  • 400 W output powers everyday desktop builds
  • 70 % typical-load efficiency lowers running costs
  • Dual +12 V rails supply stable power to drives and CPU
  • ATX 12V V2.3 compliance ensures broad motherboard compatibility
  • Multiple protection circuits guard against over-voltage, over-current and short circuits

Cooler Master Elite 400W ATX supply

The Cooler Master Elite RS400-PSARJ3-US is an ATX12V 400W power supply built for everyday desktop computing. It uses high-performance components to deliver a durable power source for standard office or home systems. Compliance with ATX 12V v2.3 ensures compatibility with modern motherboards. Dual +12V rails provide ample power for additional hard drives and components.

Sustained-load behaviour and efficiency

The unit delivers more than 70% efficiency at typical load operation, reducing wasted energy during continuous use. A green power design meets Energy Star and Blue Angel requirements for lower environmental impact. Multiple protection circuits including OVP, OCP, OPP and SCP guard hardware under prolonged stress. EMI and noise filtering is built in to maintain stable output over long sessions.

Installation notes and common pitfalls

A single 4+4 pin +12V CPU connector is provided for high-end CPU support, so builders needing two EPS connectors cannot use this unit. The dual +12V1 and +12V2 outputs require correct load balancing across rails for stable operation. AT form factor limits use to compatible cases and motherboards only. No modular cabling means unused leads must be routed inside the chassis.

Highlights

  • 400 W output powers everyday desktop builds
  • 70 % typical-load efficiency lowers running costs
  • Dual +12 V rails supply stable power to drives and CPU
  • ATX 12V V2.3 compliance ensures broad motherboard compatibility
  • Multiple protection circuits guard against over-voltage, over-current and short circuits

Specifications

TypeAT

Questions about this item

How loud or hot does the 400W unit get when running all day?

The supply uses high-performance components and an EMI and noise filter built into the design to keep acoustic and thermal output low during continuous operation.

What else must I already own for this 400W ATX supply to work?

You need a standard ATX chassis, a motherboard with a 24-pin ATX connector and a 4+4-pin +12V CPU connector, plus the drives and expansion cards you intend to power.

Will the dual +12V rails at 400W handle older hard drives and add-in cards I plan to keep?

Dual +12V1 and +12V2 outputs provide ample power for additional hard drives and components, while multiple protections (OVP, OCP, OPP, SCP) safeguard legacy parts.

Also in this aisle

People compared these

Same shelf, same checkout — eight coins and a 30-minute rate lock.