I cannot hide it; I am a big fan of the Corsair RMx PSUs because they offer high performance and reliability at a price that won’t empty your wallet. Currently, the RMx members are among the best in the mid-price category, in every Wattage, from 550W up to 1000W. The OEM of this line is CWT, which also made the previous RMx models, and the exterior design allows you to distinguish the new RMx units from the older ones easily. The triangular perforations on the punched fan grill and the front exhaust are characteristic of Corsair’s fresh PSU designs.

Component heavyweight Corsair periodically updates its range of power-supply units (PSUs) to incorporate new features and technology. It has been three years since the popular RMx line had a makeover, and Corsair believes there is enough new to warrant a range update. Credit is provided by Novuna Personal Finance, a trading style of Mitsubishi HC Capital (UK) PLC, authorised and regulated by the Financial Conduct Authority. Financial Services Register no. 704348. The register can be accessed through http://www.fca.org.uk We find it curious that Corsair bundles three 8-pin CPU cables for this 850W model. Very few boards demand this level of power - AMD Ryzen Threadripper, mostly - so it's more of a keeping-the-bases covered kind of move than of current practical value. It actually makes more sense on the 1,000W model, which also has a trio of CPU plugs.More compact size, uses a 120mm fan instead of 135mm, different manufacturer and design, cheaper non-Japanese capacitors, lower temperature rating 40°C vs 50°C on the RMx, shorter warranty. Marketed as being "Low noise" it's actually no better than the other RM/RMx units, scoring A- in Cybenetics noise testing which is the same as the RMx 2021 and worse than the 2018 RMx which is A+ noise rating. Most likely due to using a more compact design and a smaller 120mm fan than the 135mm fans in the RMx/RM units. The ATX 3.0 standard demands a high level of reliability and power efficiency. While many CORSAIR PSUs meet these requirements, RMx SHIFT Series PSUs are formally certified for ATX 3.0compliance.

As before, five sensible capacities ply the range - 550W, 650W, 750W, 850W, 1,000W - and certification stays at 80 PLUS Gold. Let's focus on what is new.

Silent Operation: The zero RPM fan mode ensures quiet operation during low to moderate system loads, keeping noise levels to a minimum. The reason for the three EPS12V is because Nvidia originally stated that they would be adapting 2x EPS12V to 12-pin for the Ampere FE cards. Then, at the last minute, changed that to 2x PCIe to 12-pin. By then it was too late to change the RMx cable configuration. The RM850x is my current (primary-PC) PSU ,for about 2 years now and i’m extremely satisfied by its performance. The Corsair RM850x is designed to provide reliable power to various computer components. Its specifications indicate that it can handle demanding power requirements for high-performance systems. The presence of a single fan with a 135 mm diameter suggests effective cooling, which is crucial for maintaining stable performance and preventing overheating.