A 120mm rifle bearing fan with a specially calculated fan curve keeps fan noise down, even when operating at full load. Corsair innovations, like the first DSP-controlled desktop PC power supply, drive our focus on providing reliable, quiet and efficient PSUs for everything from basic desktop systems to one-of-a-kind dream PCs.

The main subject of today's review will be the RM850, which, as its model number implies, has a capacity of 850 W, making it the second-strongest RM unit. And when you're pushing it hard, the thermal sensor controls the fan speed to ensure that it gets the cooling it needs without any extra noise. An additional resistor has been added that will result in the fan turning on prior to the condition that causes the PSU to shut down in the event that temperatures exceed 45°C. Had a few shut downs while gaming the past week and couldn't understand why, but seems this is the likely cause. While some fanless units have orientation requirements, the RM Series can be mounted in any position just like any other actively cooled power supply.

The first four digits of the serial number correspond with the date of manufacturer, so if a change is made in production, those numbers are going to be the best way to track it. Powering an i5-4570, 2x4gb Vengeance Ram, a single GTX660, Asus Xonar Soundcard, 2 hard drives, 3 fans (one on Hyper 212 CPU cooler) spinning really (400 rpm) slowly. In a sudden move a few days ago, they released the RM series sitting right between the HX and TX line. Complement your system's look with CORSAIR Premium Individually Sleeved Type 4 Gen 4 PSU Cables (sold separately), available in seven different colors and patterns. While this is a design flaw that should have been avoided, I must say the way Corsair are handling this and your support is excellent.

Connect it to your Corsair Link system (available separately) and you can even monitor fan speed and +12V current directly from your desktop. For consistent, reliable power and superb electrical performance, each RM Series power supply features a robust resonant LLC topology with DC-DC conversion and 105°C rated industrial-grade capacitors.The latter admittedly sounds a little strange since the higher HX series doesn't utilize a fully modular cabling design, but the "lesser" RM units do, and they are even Gold certified, sporting the same efficiency as the HX units. The custom-designed fan has an optimized blade profile for low-turbulence airflow and near-silent operation even at full speed.