Corsair RM850i Fully Modular 850W Power Supply Review

Final Thoughts and Conclusions

The Corsair RM850i power supply exhibited excellent voltage regulation with excellent AC ripple suppression, even at full load. The power supply features a good assortment of all modular cables and delivers very good efficiency, easily meeting the 80Plus Gold criteria. The RM850i PSU incorporates a Zero RPM silent cooling mode (up to ~40% load) and continues to operate quietly even as the load increases, thanks to a high-quality cooling fan that features fluid dynamic bearings and custom designed fan blades. Because the fan speed remains so low (quiet) at mid power level the PSU runs a little warm, but the fan profile can be customized via Corsair Link if you desire.

All four of the RMi power supplies incorporate an imbedded microcontroller (analog to digital bridge) to communicate vital information to the Corsair Link software via USB. This allows the user to monitor and log fan speed, temperatures, current and voltage of the +3.3V, +5V, and +12V rails, monitor power out, display power in and efficiency, and enable/disable OCP on the +12V rails, enable/disable multi +12V rail operation and create custom fan speed profiles. Previously, some of these features were only available on Corsair’s more expensive HXi and AXi Digital Series power supplies.

Overall, the new RM850i proved to be a very good power supply (excellent performance and quiet operation). It only sacrifices a few of the AXi Series premium features (like even tighter voltage regulation and advanced Corsair Link control) for a more affordable price point.

The new Corsair RM850i power supply should start entering retail channels later this month.

•    MSRP for the RM650i PSU: $129.99 USD
•    MSRP for the RM750i PSU: $139.99 USD
•    MSRP for the RM850i PSU: $159.99 USD
•    MSRP for the RM1000i PSU: $189.99 USD

Strengths:
•    Very quiet operation: zero RPM mode up to ~40% load
•    7-Year Warranty and Comprehensive Customer Support
•    80 PLUS Gold certified, with at least 90% efficiency at 50% load
•    Supports Corsair Link digital interface
•    Excellent voltage regulation (±2%)
•    Stable power (up to 50°C) with very low AC ripple and noise
•    Fully modular cables for easy installation and to improve airflow
•    Fluid dynamic bearing fan for long life and quiet operation
•    Fan Test button
•    High quality components including all Japanese electrolytic capacitors
•    Active Power Factor correction (0.99) with Universal AC input
•    Safety Protections : OCP, OVP, UVP, SCP, OTP, and OPP

Minor Weaknesses:
•    Low fan speed (quiet) causes PSU to run a little warm at mid power levels

Corsair RM850i Fully Modular Power Supply

Our thanks to Corsair for sending us the RM850i PSU to review!