Specifications

Efficiency is 80 Plus Gold, and the unit is compatible with the newest ATX 2.4 spec (or 1.31 revision), which brings several updates over the previous version. All ATX 2.4 PSU are normally also Haswell ready, supporting the new sleep states Intel introduced with Haswell.

The RM850 has all protection features, including OTP (Over Temperature Protection), which is essential in semi-passive units, especially if their maximum operating temperature is only 40°C. We find it pretty strange that Corsair rated their new RM units at only 40°C since all RM units feature a semi-passive operation, which will inevitably lead to increased operational temperatures.

At 18 cm long, the RM850's dimensions are quite large. However, most chassis will accommodate it without a problem. Its warranty is long enough at five years, and the price Corsair asks for the unit looks pretty nice if we take its specifications and features into account.


There is only one +12V rail. It can deliver the unit's full power if needed. The minor rails are very strong with 150 W maximum combined power, and the 5VSB rail has the typical current output for a unit of this capacity.

Cables & Connectors, Power Distribution

This unit is equipped with an adequate number of cables. You have two EPS and six PCIe connectors at your disposal, and you can connect numerous drives and peripheral devices to its SATA and peripheral connectors. Cable length is also good; however, we would like the 4-pin Molex connectors to be spaced apart further, at least 13-15 cm. The Corsair Link cable has two headers that connect to the Corsair Link system sold separately; and it allows the PSU to connect with a USB header on the mainboard. All cables are 18AWG, which is the size the ATX spec recommends.

Since this PSU features a single +12V rail, we do not have anything to comment on about its power distribution.