NH-D15 G2 The further improved second generation of Noctua’s iconic NH-D15. With its state-of-the-art, speed-offset NF-A14x25r G2 PWM fans, eight heatpipes and asymmetrical fin-stacks that have been carefully fine-tuned to work in tandem with the new fans, it achieves even better quiet cooling performance than its award-winning predecessor. As such, the G2 version is a true flagship model that continues the legacy of the original NH-D15 by pushing the boundaries of air cooling and rivalling the efficiency of many all-in-one (AIO) water cooling solutions. In addition to its further improved performance, the NH-D15 G2 also offers enhanced compatibility thanks to an offset construction that allows it to clear the top PCIe x16 slot on most current motherboards. Last but not least, the G2 version has been upgraded to the Torx -based SecuFirm2+ multi-socket mounting system with included NM-SD1 screwdriver as well as to Noctua’s superior NT-H2 thermal compound. In short, the NH-D15 G2 has been further refined in virtually all respects from the heatsink and the fans all the way down to the mounting, thermal paste and accessory package.