Overview

The Corsair RM850x (2024) is a fully modular ATX power supply with 80 PLUS Gold certification. Part of the well-regarded RMx series, it features a 135mm fluid dynamic bearing fan with Zero RPM mode for silent operation under low loads. With 850W of continuous output, it comfortably powers mid-range to high-end gaming builds.

Key Features

  • 80 PLUS Gold certified (up to 90% efficiency) — lower electricity bills and less heat
  • Fully modular cables — connect only what you need for a clean build
  • 135mm FDB fan + Zero RPM mode — completely silent at idle
  • Japanese capacitors — long-term reliability
  • 10-year warranty — peace of mind

Compatibility Guide

  • Form factor: ATX (fits standard PC cases)
  • Connectors: 24-pin ATX, EPS12V (dual 8-pin CPU), PCIe 6+2-pin x4, SATA x9, peripheral x4
  • Recommended PSU wattage: 850W (this unit's rating)
  • Case clearance: 160mm depth — fits most ATX cases; check dimensions for compact cases
  • Note: This PSU is not ATX 3.0/3.1 compliant. For RTX 40/50 series GPUs with 12VHPWR connectors, you'll need the included adapter or a separate Corsair Type 4 12VHPWR cable.

Ideal Builds

  • Mid-range to high-end gaming PCs (e.g., Ryzen 7 + RTX 4070 Ti Super / RX 7800 XT)
  • Silent-focused builds (Zero RPM mode for near-silent idle)
  • Users who want a reliable, long-lasting PSU
  • Builders who value clean cable management (fully modular)

Upgrade Considerations

  • 850W is sufficient for most current builds, but if you plan to upgrade to a flagship GPU (e.g., RTX 5080 / RX 9070 XT), consider a 1000W+ unit for headroom.
  • Lack of native ATX 3.0 support means you'll need an adapter or aftermarket cable for 12VHPWR GPUs.
  • Always verify case depth (160mm) fits your chassis, especially in small form factor builds.
  • Over-speccing is rarely a problem, but balance your budget and future plans.