”Keep in mind that while the test results aren't overwhelmingly spectacular, consumers are offered more options depending on what they're looking for. The Noctua NF-P14 was a "convertible" fan. It had 120mm hole spacings with 140mm extensions with a round frame, so it could fit 120mm or 140mm mounts However, like a real convertible with the top down, it's a bit louder. Round framed fans in general perform much better on air cooling radiators, but square framed fans in general perform better on watercooling radiators. Thus, you now have the option to choose between a variety of 140mm (and 150mm) fans from Noctua. Whether you're looking for the most optimal silent solution with the NF-A14 ULN, or a quieter replacement to the NF-P14 with the NF-A14 FLX that still does a great job with the U.L.N.A. adapter. The NF-P14 is still a solid performer and the NF-A15 PWM is a great replacement for 120mm fans where size isn't a factor. Decisions, decisions!”



Link: OCC