The new Corsair RMx PSUs have ASM compatibility and perform as well as their predecessors, while even improving on them in some key areas, including efficiency at very light and light loads. The ML fan is a great addition. Not that the riffle-bearing fan on the previous generation wasn't good, on the contrary, but ML fans are better since they do not have any problems operating under high operating temperatures for prolonged periods. Another major change is the third EPS connector with the 850 W and 1000 W RMx models. I can't help but wonder which CPU will need this many EPS connectors, but Corsair will have their reasons.

Competition in the 850 W Gold category is fierce. Still, the Corsair RM850x performs well, placing third in my relative performance chart, with only a small gap to the Seasonic Focus Plus Gold of similar capacity and the EVGA SuperNOVA 850 G3, which the inferior G5 model has replaced. Practically, the RM850x and Focus GX-850 are the leaders in the 850 W category. Another notable mention in this wattage range is the Thermaltake ToughPower GF1 850, which also uses a CWT platform.

Corsair's RMx line is among the most popular in today's market. The new models will carry on this tradition if actual prices are kept the same since their performance is even higher and they are fully compatible with the newest ATX specification (v2.52). The only thing that needs tuning is the fan-speed profile under high loads on the minor rails. There is no need for such a high maximum combined power limit on the minor rails (150 W), and if Corsair were to lower the limit to 100 or 120 W, the Cybenetics noise rating would improve as well. That having been said, ARGB does put a strain on the 5 V rail, so lately, there is a demand for beefier DC-DC converters for that rail.

The Corsair RM850x is a fine product and deserves our Highly Recommended badge.