For an entire decade, the original NH-D15 was widely regarded as the best air cooler on the market. The G2 version continues this legacy by further improving the renowned quiet cooling performance of its iconic predecessor. Especially in challenging conditions with higher heat-loads, the NH-D15 G2 can achieve up to several degrees lower temperatures and thereby offer a thermal headroom that enables higher turbo clock speeds.
The NH-D15 G2 has been painstakingly optimised to best utilise the superior airflow and pressure performance of the novel NF-A14x25r G2 fans. Thanks to the fans’ improved P/Q performance, the fin-spacing could be reduced from 1.9mm to 1.6mm, which made it possible to integrate 26 extra fins and increase total fin surface area by 20%. At the same time, the width of the front fin-stack has been cut by 5mm so that the loading is more balanced between the two fans.
Thanks to the higher fin density made possible by the new NF-A14x25r G2 fans as well as the asymmetrical fin-stacks and a slightly smaller gap between the stacks, the G2 version combines improved performance with a slightly smaller size compared to the original NH-D15 (9mm less heatsink depth, same heatsink width, same total height including fans).
The NH-D15 G2 utilises eight instead of six heatpipes compared to the original NH-D15. The increased thermal capacity of the extra heatpipes is especially helpful at extreme heat-loads such as 250W and beyond, where the performance boost over the original NH-D15 is the biggest.
Optimal contact quality between the heatsink and the CPU is vital for achieving the best possible cooling performance. Since current CPU platforms differ significantly in terms of contact surface flatness and hotspot location, the NH-D15 G2 is available in a regular all-round version with medium base convexity as well as specialised LBC (Low Base Convexity) and HBC (High Base Convexity) variants in order to ensure the best possible contact in different scenarios.
The regular NH-D15 G2 uses the same medium base convexity as most other Noctua heatsinks, which makes it a perfect all-rounder that provides optimal results on AM5 with the included offset mounting and on fresh, unused LGA1700 CPUs when utilising the included NM-ISW1 shim washers or so-called contact frames to reduce CPU deformation from ILM pressure. For further details, see this FAQ.
Adding 1mm shim washers underneath the LGA1700 socket’s ILM (Independent Loading Mechanism) will lower the pressure that the ILM exerts onto the CPU and thereby reduce the deformation that occurs due to this pressure. With the CPU being deformed less, the contact between CPU and low or medium convexity heatsinks will improve, which can yield typical temperature improvements of around 2-3°C. CPUs that have been used with full ILM pressure for longer periods of time may also see slight improvements with high base convexity coolers. For further information, please see this article.
Like the NH-D15S, the NH-D15 G2 is offset towards the upper edge of the motherboard (when installed in standard orientation blowing towards the I/O panel) in order to increase clearance towards the PCIe slots. This enables it to clear the top PCIe x16 slot on most current motherboards (see motherboard compatibility list).
Thanks to its recessed lower fins, the NH-D15 G2 provides at least 59mm clearance for tall memory heatsinks in single fan mode, making it compatible with most high-end RAM modules on the market. In dual fan mode, the NH-D15 G2 should either be used with standard height RAM (up to 32mm) or, in chassis with more than 168mm CPU cooler clearance, the front fan can be moved upwards to make room for memory modules taller than 32mm.
Noctua’s next-generation NF-A14x25r G2 fans set a new benchmark for performance-to-noise efficiency in round-frame 140mm fans. Their superb acoustics as well as their superior airflow and pressure characteristics are one of the cornerstones that enable the NH-D15 G2 to push beyond its legendary predecessor.
When two fans operate in a push-pull configuration running at the exact same speed, their acoustic interaction can lead to undesirable harmonics phenomena such as intermittent vibrations or periodic humming. Therefore, the two NF-A14x25r G2 PWM fans used on the NH-D15 G2 are slightly offset in speed (+/- ~25rpm) in order to ensure optimal acoustics.
The NF-A14x25r G2 PWM fans can be PWM-controlled from their maximum speed of 1500rpm all the way down to 300rpm. This makes it possible to adjust them for maximum performance or near-silent operation using either automatic, temperature-based motherboard speed control or manual controllers such as the NA-FC1.
When the fans are set to 0% PWM duty cycle by the motherboard or PWM fan controller, they will stop. This makes the NH-D15 G2 ideal for creating setups with semi-passive cooling that automatically turn the fans off and thus run completely silent at idle if thermals allow.
The NH-D15 G2 is supplied with two Low-Noise Adaptors (L.N.A.) that reduce the maximum fan speed from 1500 to 1250rpm. The L.N.A.s can be used either to run the fans at a fixed speed of 1250rpm or to cap the maximum speed when using automatic PWM control.
Extending below the fin-stacks, the large NF-A14x25r G2 fans not only contribute to the NH-D15 G2’s superb CPU cooling capabilities, but also provide massive airflow over surrounding motherboard heatsinks and components such as VRMs, thus ensuring excellent component cooling performance.
Noctua’s SecuFirm2™ mounting systems have become synonymous with quality, safety and easy installation. Torx-based, the professional SecuFirm2+™ version with its included screwdriver provides even better handling and durability. Socket support includes AMD AM5 and AM4, as well as Intel LGA1851, LGA1700, LGA1200 and LGA115x (LGA1150, LGA1151, LGA1155, LGA1156).
The NH-D15 G2 includes Noctua’s offset mounting bars for AM5 that make it possible to install the cooler shifted towards the south side of the socket by 7mm, thereby achieving better contact quality right above the CCD(s). This can help the LBC version to edge out another few tenths of a degree, enables the regular version to perform on par with the LBC version and puts the HBC version within close range. For detailed data, see this article.
Thanks to Noctua’s SecuFirm™ ecosystem, the NH-D15 G2 chromax.black can be made compatible with the older LGA20xx (LGA2066, LGA2011-0 and LGA2011-3 Square ILM), LGA1366 and LGA775 sockets using optional mounting kits, which are provided through Noctua’s website free of charge. If technically possible, Noctua will also provide upgrade kits for future sockets, which makes the cooler a safe long-term investment.
When the mounting pressure of the cooling solution is applied, excess thermal paste will be squeezed outwards. With AM5 CPUs, this excess paste tends to accumulate in the cut-outs at the sides of the heatspreader and may become difficult to remove. Simple and risk-free to apply, the NA-TPG1 prevents this undesired phenomenon.
With many heatsinks, the fins are press-fitted to the heatpipes. Due to the different thermal expansion coefficients of copper and aluminium, this fit can loosen over years of thermal cycling, which may lead to reduced performance. By contrast, the NH-D15 G2’s fins are soldered to the heatpipes in order to guarantee a superior thermal interface that doesn’t deteriorate even after many years of usage.
Noctua products are renowned for their impeccable quality and outstanding longevity. True to this legacy, the NH-D15 G2 heatsink is built to last, and like all Noctua fans, the supplied NF-A14x25r G2 units feature an MTTF rating of more than 150,000 hours. The entire package comes with a full 6-year manufacturer’s warranty.
