Like its bigger brother I evaluated a while ago, the Pure Power FM 650 W proved to be a solid performer. The OEM switch from FSP to CWT did the trick—these new be quiet! units easily meet the competition head on. The performance differences to the XPG Core Reactor 650, new Corsair RM650x, and Thermaltake Toughpower PF1 are minimal. Moreover, honoring the be quiet! company name, the Pure Power FM 650 loses only to the Corsair RM650x when it comes to average noise output.

To keep the price reasonable, be quiet! made some compromises, mainly in the capacitor selection. I am not pleased to see 85 °C rated bulk caps, especially as the competition uses higher-quality caps for the APFC converter. The Teapo SC caps with their low lifetime on the secondary side don't look good, either. However, be quiet!'s PSU PM assured me that these parts won't cause any issues and will outlive the five-year warranty, which is pretty long. I don't have any reason not to believe him, but would prefer paying a few more dollars for better caps that are on par to those the competition uses. We probably are all spoiled by the incredibly long warranty periods most brands provide nowadays, which reach ten years in this market segment. Such a long warranty period sounds crazy for a PSU, whose well-being heavily depends on the quality of the mains grid and the operating conditions. As such, many brands use the best-possible parts for critical circuits that are stressed heavily to ensure there will be no problems.

Another issue could be the high inrush current with 230 V, and CWT should address this soon. Thankfully, it is hard to drain the bulk caps completely and face the worst possible scenario, but some of you may still manage to do so. With that in mind, the inrush current protection circuit should be more effective.

The Pure Power FM line looks highly promising since the two members I evaluated thus far easily meet the competition in their respective categories and are priced decently. If you look at the pros list, you will quickly figure out why I chose to award this product our Highly Recommended badge.