Noctua is primarily known for its highly efficient air coolers that offer high performance and are also surprisingly quiet. Yet, some customers want to have a PC that produces no noise at all and who prefer fanless cooling systems and cases. Bringing Noctua's expertise to passive coolers has always been something that its customers were enthusiastic about, and it looks like their dreams are about to come true 'very soon.'
Noctua first demonstrated its prototype fanless CPU cooler in mid-2019 at Computex. The tower heatsink featured multiple aluminum fins, six heat pipes, and weighed in around 3.3 pounds (1.5 kilograms). It was designed to cool a CPU with an (up to) 120W TDP in a completely fanless case, or a processor with an (up to) 180W TDP in a case equipped with quiet fans, or when equipped with a fan itself. The device was designed primarily for AMD's AM4 and Intel's LGA115x platforms, though it is reasonable to expect it to be compatible with LGA1200 and eventually LGA1700, too.
Noctua is traditionally very serious about its R&D process and validation of its products, so it took the company quite a while to finalize its passive CPU cooler. Noctua's latest roadmap indicates that the fanless cooler is set to be launched in Q2 2021. When asked to be slightly more precise, a company's representative said on Twitter (via TechPowerUp) that the unit is 'coming very soon.'
Recently Noctua talked about challenges it faced designing its fanless CPU cooler. Given how modern desktop processors work and their bursty behavior, their cooling systems have to remove relatively large amounts of heat at all times. Therefore, a passive cooling system for a processor is not just a large heatsink with loads of fins and without a fan (as such a design is intended to work with a fan or even two fans to be efficient) but is a completely different device from an engineering standpoint.
"The key challenge is that for a passive cooler to be truly effective, design parameters such as fin pitch and fin thickness need to be quite different," said Jakob Dellinger, a representative for Noctua, in an interview with RelaxedTech. "You need a certain pitch to get low enough flow resistance for sufficient natural convection and a certain fin thickness in order to get the mass that is required for absorbing enough thermal energy."
"This means that different manufacturing machinery is required, e.g., much stronger stamping presses, etc. Getting this sorted in a reasonably cost-efficient way was quite a challenge. […] We found the technical possibility thrilling and hope that many customers will share this feeling. There’s a certain beauty and simplicity to going completely fanless rather than just running slow fans, there’s no real possible point of failure, less dust build-up, and of course, the bliss of complete silence."
Noctua has yet to disclose the pricing of its passive cooler, but at least we now know that the product is set to hit the market shortly.
Imagine a Ryzen 9 5900x running without fans, or (shocker) an i5-11400.