We would like to thank Corsair for supplying the review sample.
Corsair has grown into a huge company over the last several years, and they are still constantly expanding on all areas they participate in. Especially their PSU portfolio has expanded rapidly lately as we saw Corsair release one line after another, which put the competition into a really uncomfortable position. The fresh RM line is, according to Corsair, optimized for silence, and our experience with the RM750 and RM850 units we already reviewed a while ago confirms just that since both aforementioned units registered very low noise output throughout their entire operating range. We would also like to remind you that the RM750 and RM850 units are made by Chicony while all other RM PSUs are made by Channel Well Technology (CWT), an OEM Corsair has cooperated with successfully for a long time. The RM650 is then based on a different platform than its two bigger siblings, and we are really curious to see how it will perform.
The RM650 is 80 Plus Gold Certified and features a fully modular cabling design, like all RM units. It is also very silent because of its relaxed fan profile and semi-passive mode feature, which only enables the fan when the unit's internal temperature reaches a rather high threshold. The RM650 uses Corsair’s NR135L fan, a custom-design that provides the lowest possible output noise and a near-silent operation at even full speed. We are in a position to confirm Corsair's claim to silence since the same fan is used by all RM units and we have already tested two of them. Another interesting feature of the RM units is their compatibility with the Corsair Link software. However, neither is digital, so only two measurements can be taken through the software: fan speed and current output of the +12V rail. The only downside here is that you have to purchase an additional cable to connect the PSU with a USB header of your mainboard. Corsair apparently didn’t want to further increase the cost of RM PSUs, not even by a few bucks, since Corsair Link only offers two possible readings with this particular PSU.