This is probably the best HEC platform I have evaluated so far. Without any doubt, be quiet! properly guided HEC towards building a platform capable of delivering good results. The competition from Corsair and CWT is stiff, though, so overall performance is still lacking compared to the RM850 and RM850x. The latter is sold for $20 more than the MSRP of the Pure Power 11 FM 850. Still, the RM850 is currently sold for $5 less, making it formidable competition since it is quieter and uses higher-quality caps. It is supported by a ten-year warranty, while be quiet!'s offering comes with a five-year warranty. In my eyes, anything above ten years for the warranty is overkill, but Corsair, EVGA, and Seasonic set the bar high in this regard, "spoiling" the majority of buyers, who select their new PSU based on the provided warranty.

The area where I expected be quiet! to have a notable lead over the competition was noise output, but the FM 850 failed to live up to my expectations. You cannot call it noisy, but the fan profile needs tuning to drop average noise output below 25 dBA. With the large internal heatsinks and efficient platform, the only thing I can think of keeping HEC's engineers from loosening the fan-speed profile is the mainstream Teapo SC caps that are best kept as cool as possible for them to outlive the five-year warranty without any issues.

The be quiet! Pure Power 11 FM 850 W is a good PSU, but the competition is tough. Some changes are required to increase performance and better compete with Corsair, EVGA, ASUS, and Seasonic. A price drop would also help. With street pricing close to $100–110, the Pure Power 11 FM 850 W would be worth considering, especially in the US.