As I already mentioned, the RM650 uses a different platform from that of the RM750 and RM850 units I tested in the past, so it doesn't have the annoying, at least to me, problem of the fan engaging rather late. I read of Corsair admitting that the fan of the aforementioned units starts very late, which can sometimes cause unexpected shutdowns, though such shutdowns never happened in my reviews despite pushing both units really hard. That said, the fan engaging when it did wasn't my primary concern as I was more troubled by how long the lower quality caps used in the bigger RM units would last under such tough conditions. CWT was thankfully more conservative by using a less relaxed fan profile while also tuning the semi-passive operation to disengage at a lower internal temperature threshold, which ensures that heat sensitive components like electrolytic capacitors are put under less duress, making them last longer. Well, all Corsair RM units are covered by a hefty five year warranty, and Corsair honors the warranties they provide, but broken PSUs are trouble and inconvenience owners even if they get replaced fast. What I didn't expect from CWT was the missing earth bridge on the modular PCB, which disabled some of the 5V wires of the ATX connector. Not a significant problem since the rest can easily cope with the task, I still wonder how they missed it; they apparently rushed to release the unit.

The RM650 exhibited generally nice performance with good overall voltage regulation, low ripple, and high enough efficiency for its platform, and throughout its entire load range, especially at lower loads. It also operates silently at up to medium load, and its fully modular design gives it an edge over the semi-modular competition. Buying the optional Corsair Link cable will also allow you to monitor +12V amperage and the fan's speed through the corresponding software. I don't know if it is worth the money for only two readings, but it will most likely not be expensive. I would personally prefer it if Corsair were to provide better caps in the secondary side instead of Corsair Link compatibility, but Corsair Link provides a "wow" factor while capacitors are internally hidden components most people don't even know the look or purpose of in a PSU (reliability and the maintenance of good performance over time).

To sum up, I think the RM650 is a decent choice for users that want to build a very quiet system without investing into a passive PSU, or those simply in need of more power than what passive units can provide. However, those users will also find good alternative options with a quick search around, and in the same price range.