Noctua makes coolers that are primarily known for their quiet fans and efficient design. But no matter how quiet your fans are, they're still not absolutely silent. To be absolutely silent, you need to go fanless, and that's exactly what Noctua has done with its NH-P1 cooler.
The Noctua NH-P1 doesn't have a fan yet claims compatibility with all modern AMD and Intel CPUs, including AMD's AM4 as well as Intel's LGA1200, LGA115x CPUs. While the NH-P1 is designed primarily for chips featuring moderate power consumption, it can also be equipped with a 120-mm fan (the manufacturer recommends its NF-A12x25 LS-PWM) for advanced processors that run hotter.
The NH-P1 cooler features a mostly aluminum construction with 13 thick fins to dissipate thermal energy fast. To absorb heat rapidly, the unit has a copper base and six copper heat pipes.
Noctua's NH-P1 cooler measures 158×154×152 mm and weighs 1180 grams, large enough that it won't fit into a small PC case. It should be capable enough for cooling mainstream CPUs rated for 65W TDP (there is an official list of compatible CPUs (opens in new tab)). Keep in mind that Intel's 65W CPUs can consume and dissipate much more than 65W in burst mode, so passive coolers must be used with BIOS tweaking.
Noctua did not disclose its recommended price for the NH-P1 cooler, but it's reasonable to expect it to cost in the $100/€100 ballpark given the specifications and capabilities. Amazon lists the cooler (opens in new tab) for $110 in the US, with Prime shipping. Availability elsewhere may be limited.