**UPDATE**: For updated K2 results, have a look at our revised testing

The results have been arranged in terms of the fan configuration that yields the best results for each cooler. However, it is important to take into account that many coolers come with their own fans and changing those increases the costs significantly, so the “out of the box” cooler configurations have been highlighted in red each group.

Stock


The Alpenföhn K2 gets off to a very promising start, landing 5th by group measurement. Ignoring the two ALC coolers for now (they rely on deafeningly loud fans for such good performance), the K2 ends up just behind the Phanteks and Noctua NH-D14. Let’s first take a look at the various fan configurations tested. Starting off with the default configuration comprising of the two 120/140mm Wing Boost fans, the delta temperature is an impressive 30.75C. Reducing their respective speeds of 1500/1100RPM to 60% through PWM functionality, the temperatures increase by 3C, and still delivering excellent performance with inaudible levels of noise. Using only the middle 140mm fan, temperatures are only 1.5C worse than the default dual fan configuration.

Switching the fans to Noctua’s NF-P12s yields a delta temperature of 31.5C, 0.75C more than the default configuration. The larger NF-P14s, although still lagging behind the stock fans, perform marginally better than their siblings. Opting for the higher RPM SWiF2-120P generates performance to match the two stock fans, the downside being that the setup ends up much louder. The best configuration, not surprisingly, is when three fans were installed thanks to Alpenföhn bundling some extra fan clips. The main observation here is that the two stock fans are perfectly adapted to the cooler and perform better than Noctua fans, an observation we also made on the Matterhorn. Another observation is that two Wing Boost 140s don’t perform as well as the 120/140mm configuration.