Despite the fact that the prices of 360mm liquid coolers have become very affordable, many DIY users still prefer air coolers, as they offer higher stability, longer lifespan, and no risk of leakage compared to liquid coolers. NOCTUA, known for its reputation in the field of air coolers, has been focusing solely on air coolers for many years, thus attracting a large following. The NH-D15 is a classic high-performance air cooler from NOCTUA, and after continuous upgrades and iterations, the all-new NH-D15 G2 has finally hit the market this year. Compared to the previous generation, the NH-D15 G2 has been upgraded from 6 heat pipes to 8 heat pipes. So, does the newly upgraded NOCTUA NH-D15 G2 still hold its ground against numerous competitors?

Product Specifications:

NSPR Value: 228

Heat Pipe Specification: 8 heat pipes

Fin Material: Aluminum

Product Dimensions: 168mm x 150mm x 162mm (including 2 fans)

Tower Process: Reflow soldering

Base Process: Nickel-plated copper reflow soldering

Supported Platforms: AMD AM5/AM4; Intel LGA1851/LGA1700/LGA1200/LGA115x

Number of Fans: 2Fan dimensions: 140mm × 140mm × 25 mm

Fan bearing: SSO2

Maximum speed: 1500 RPM (with a deviation of 50 RPM between the two fans)

Speed with noise reduction cable: 1250 RPM

Maximum airflow: 155.6 m3/h; with noise reduction cable: 127.1 m3/h

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Fan static pressure: 2.56 mm H2O; with noise reduction cable: 1.3 mm H2O

Noise level: 24.8 dB(A); with noise reduction cable: 19.7 dB(A)

Warranty period: 6 years

Reference price: 1199 yuan

Still familiar with the family-style appearance designAs an internationally renowned radiator brand from Austria, Noctua enjoys a high reputation among DIY enthusiasts. Even those who have not personally experienced its products are familiar with the name. Its iconic brown packaging and appearance color scheme serve as a unique business card for the brand, highly recognizable and unforgettable.

Specifically, the NH-D15 G2 radiator continues the classic style of its predecessor, the D15, with a design that brings back the "familiar taste." This design leans towards tradition, with a simple structure and no fancy elements, which aligns well with the aesthetic needs of users who pursue minimalism.

The NH-D15 G2 continues to adopt a dual-tower structure, which is also the mainstream design for mid-to-high-end air coolers. Its two fans are secured to the heat sink fins with metal wires. Since it does not use a closed top cover design, the disassembly and assembly of the radiator are simpler, and it facilitates later maintenance.

There are three versions to suit your needs:

The Noctua NH-D15 G2 comes in three versions: the standard version, the LBC version, and the HBC version. We recommend choosing the NH-D15 G2, which uses a medium convex base similar to most other Noctua radiators, meaning the standard version is relatively more comprehensive. Why does it offer three versions with different convex base heights? This is because different processor surfaces may be completely flat, or they may have a slight concave shape after being used for a while, influenced by the pressure of the previously used radiator. If the radiator is replaced, the contact quality may decrease, thereby affecting the cooling performance.

The standard version of the NH-D15 G2 features a medium convex design, the LBC version has a low convex design, and the HBC version has a high convex design. The standard version, with its moderate convexity, can adapt to various mainstream processor surfaces and provide relatively good cooling performance. The LBC (Low Convex Base) version is specifically optimized for relatively flat processors, such as providing excellent contact on processors for platforms like AMD AM5/AM4, LGA2066, LGA2011, etc. The HBC (High Convex Base) version is specifically optimized for LGA1700 processors used under full ILM (Independent Load-Bearing Mechanism, commonly known as "clips") pressure or those that have deformed over time. Despite the concave shape of the processor surface, this version still provides excellent contact quality.

So, how to choose among these three versions? The prices of these versions are the same. It is recommended to choose the standard version first. For processors on the LGA1700 platform to reduce pressure from the ILM, it is suggested to use the included 1mm "NW-ISW1" spacer with the radiator. If you are using a LGA1700 platform processor but do not want to use a spacer, we recommend using the HBC version. If you are using a processor on the AM5/AM4, LGA2066, or LGA2011 platform, the LBC version is recommended. The standard version is what MC received.Equipped with 2 NF-A14x25r G2 Fans

In air-cooled heat sinks, the performance of the fan is of paramount importance, and its quality directly affects the overall performance of the heat sink. Here, we will focus on the fan section of the NH-D15 G2. As the flagship air cooler from NOCTUA, the NH-D15 G2 is equipped with its self-designed next-generation NF-A14x25r G2 PWM fans. From the name itself, it is evident that this fan supports PWM speed control, allowing it to flexibly adjust within a speed range of 300RPM to 1500RPM according to actual needs. The heat sink also comes with a noise reduction cable, commonly known as a slow-down cable, which caps the fan's maximum speed at 1250RPM when used. Additionally, at the highest speed, the fan can deliver an impressive airflow of up to 155.6m3/h (127.1m3/h with the noise reduction cable) and an air pressure of 2.56mm H2O (1.3mm H2O with the noise reduction cable). Even when operating at the highest speed, its maximum noise level is only 24.8dB(A), and with the noise reduction cable, it is 19.7dB(A), creating an almost silent usage environment for users.

It also features NOCTUA's exclusive SSO2 bearing design, which optimizes the position of the magnets by placing them closer to the axis center. This allows for a higher magnetic force to be applied to the rotor shaft, making the bearing more stable during operation. Moreover, due to the stabilization of the axis by the magnetic field, the SSO2 bearing can reduce gyroscopic effects during start-up and the initial running phase, thereby reducing wear and noise of the bearing. In addition, the SSO2 bearing has been optimized in design and materials to extend its service life. The SSO2 bearing also incorporates oil-based fluid dynamic design, which uses the principle of fluid dynamics to lubricate and stabilize the bearing, contributing to enhanced durability and stability.

The two NF-A14x25r G2 PWM fans equipped with the NOCTUA NH-D15 G2 have slightly different specific models, namely "NF-A14x25r G2 PPA" and "NF-A14x25r G2 PPB," with corresponding speeds also having minor differences: 1475RPM and 1525RPM. Some readers might wonder why these two fans do not simply use the same speed. In fact, this design cleverly employs a speed fine-tuning strategy to achieve better noise control. The reason is that when two fans operate synchronously at exactly the same speed, the noise they generate can interfere with each other, causing undesirable harmonic effects, such as intermittent vibrations or periodic humming sounds. To this end, the two NF-A14x25r G2 fans equipped with the NH-D15 G2 have been specially set with a slight speed difference (controlled within +/-25RPM), which effectively avoids the aforementioned adverse noise phenomena and thus achieves a more harmonious noise control effect between the fans.

The NF-A14x25r G2 PWM has overall dimensions of 140mm x 140mm x 25mm and belongs to the round frame design series (with square frame and unique chromax.black black versions to be launched in the future to meet different needs). The fan features a centrifugal turbine shaft, small wing structure design, flow acceleration channels, stepped intake, SSO2 bearing technology, optimized AOO (Acoustical Optimization) frame, and innovatively uses Sterrox liquid crystal polymer material. These designs together enhance the fan's durability and efficiency. This fan is specially equipped with 9 fan blades, compared to the usual 7-blade fans, the more blades there are, the greater the airflow through the heat sink per unit of time, which can more quickly conduct heat away and improve heat dissipation. This is because more blades can cut the air into smaller pieces, making the airflow more dispersed and increasing the contact area with the heat sink.

It is worth mentioning that it also comes with a centrifugal turbulence wheel frame and narrows the gap between the blade tips and the wheel frame to 0.7mm. This detail improvement can significantly enhance the heat dissipation performance in heat sink applications. What is the concept of a 0.7mm frame-blade spacing? Many high-end cooling fans currently have a frame-blade spacing of about 1mm, and a frame-blade spacing of less than 1mm is only achievable by professional cooling giants like NOCTUA. We have also discussed the knowledge about frame-blade spacing before, which refers to the tiny distance between the outermost end of the fan blade and the inner frame of the fan, usually measured in millimeters. Do not underestimate this seemingly insignificant 0.7mm frame-blade spacing, as it has a significant impact on the fan's heat dissipation efficiency, noise level, and service life.Specifically, the size of the frame-blade spacing directly affects the air leakage of the fan. The larger the spacing, the more air leaks, leading to a decrease in the cooling efficiency of the fan. Many inexpensive fans on the market often have frame-blade spacing exceeding 1mm. Such designs, while potentially providing greater airflow, reduce air pressure and affect cooling performance. Conversely, reducing the frame-blade spacing can reduce air leakage and improve the fan's cooling efficiency. However, spacing that is too small may cause the blades to rub against the frame, creating a "sweeping" phenomenon, which can actually reduce performance. Additionally, the 0.7mm frame-blade spacing of the NF-A14x25r G2 PWM places high demands on the materials and manufacturing processes, which is why NOCTUA chose to use Sterrox liquid crystal polymer material, aiming to enhance the fan's resistance to deformation under centrifugal force, suspension, or vertical installation. Therefore, fan manufacturers need to consider these factors comprehensively when designing and producing fans to ensure they provide optimal performance and cooling effects under various conditions. This is also why high-performance fans are not cheap. Currently, this fan is not sold separately, and the expected price will exceed 300 yuan.

Nickel-plated 8 heat pipes combined with reflow soldering process

NOCTUA NH-D15 G2, as a strong competitor in the flagship air cooling field, has also surpassed itself in specifications, adding two additional heat pipes compared to the previous D15, totaling 8 high-efficiency heat pipes, further strengthening its cooling performance and the symbol of "flagship" status. Currently, the market has seen an increasing number of 8-heat-pipe air coolers, and these products are all flagship works for their respective brands to "show off their muscles."

Unlike the blackening treatment of heat pipes used in other coolers of the same level on the market, the heat pipes of the NH-D15 G2 have undergone nickel plating. As for the advantages and disadvantages of nickel plating and blackening processes, I can only say that they each have their advantages. Nickel-plated heat pipes are slightly superior in corrosion resistance and thermal performance, while blackened heat pipes perform better in preventing oxidation and enhancing thermal radiation. Nickel-plated heat pipes provide a metallic texture, while blackened heat pipes offer a more subdued appearance. The previous generation D15 also had a blackened version, and it is possible that the NH-D15 G2 will also release a blackened version in the future. The official specifications of the 8 heat pipes equipped with NH-D15 G2 are not marked, but our measurements with a micrometer show that the diameter of the heat pipes is around 6mm, which is consistent with some 8-heat-pipe coolers on the market.

NH-D15 G2 features a dual-tower design with optimized asymmetrical heat sink fins. The fin spacing has been reduced from 1.9mm of the previous generation to 1.6mm, allowing it to add an additional 23 fins and increasing the total fin surface area by about 20%. In addition, the width of the front fin group has been reduced by 5mm to balance the load between the two fans. The main dimensions of the radiator are 168mm x 150mm x 162mm (including 2 fans), and its size is not large, with an actual total weight of about 1.54kg. Generally speaking, the heavier the air cooler, the more solid its materials will be, and the number of heat pipes and the amount of fins can affect the total weight.

The fins near the bottom of the NH-D15 G2 use a concave design, which is what we commonly refer to as memory clearance design. If in single-fan mode (only the middle fan is installed), it can accommodate memory with a height of nearly 60mm, and it should be noted that the height of memory usually does not exceed 50mm, so this height can accommodate all memory on the market. If two fans are installed and the memory used exceeds 32mm, then the height of the fans needs to be adjusted, and the top of the fans may protrude above the tower. In addition, the radiator also uses an offset design, which allows for a larger PCIe slot gap. The advantage is that it provides ample space between the radiator and the graphics card.The NH-D15 G2 features a grooved design in the middle and at both ends of the tower's fins, a design that is quite common in air coolers on the market. Although the specific shapes of heat sinks from different brands vary, some use grooves, others use protrusions, and some are designed with a wavy pattern. Their purpose is to optimize performance. These different designs are to address the boundary layer effect formed by the airflow generated by the fan on the surface of the fins, which hinders direct contact between the high-speed airflow and the fins, thereby weakening the cooling efficiency. To solve the thermal bottleneck brought about by the boundary layer, many heat sink manufacturers have adopted a non-planar design on the fins on both sides of the tower, such as a structure with staggered heights. This design strategy not only successfully reduces the negative impact of the boundary layer on the cooling efficiency but also reduces wind noise.

Furthermore, to further strengthen the tight connection between the fins and enhance the stability and thermal conductivity efficiency of the overall cooling structure, the technology of interlocking Fin and folded edge Fin is widely used between the fins. Additionally, between the fins and the heat pipes, the traditional pin-through Fin process has its shortcomings in the combination of heat pipes and fins: it cannot completely eliminate the tiny gaps between the two, which also restricts the cooling efficiency. To solve this problem, the NH-D15 G2 adopts a reflow soldering process. Compared with the traditional pin-through Fin process, reflow soldering technology can achieve seamless connection between the heat pipes and the fins, completely filling all tiny gaps, thereby greatly enhancing the thermal conductivity efficiency. Generally speaking, only high-end flagship air coolers will adopt the reflow soldering process because this process has a relatively higher manufacturing cost. Mid-to-low-end air coolers use the pin-through Fin process, which can significantly reduce costs.

It is worth mentioning that the base area of the NH-D15 G2 is larger than that of the previous generation D15. A larger base is to enable the heat sink to have better thermal conductivity. Measured with a micrometer, the size specification of its base is approximately 55.5mm × 48.4mm, which can completely cover the surface of larger flagship processors. The copper base surface has also been nickel-plated, improving its corrosion resistance and thermal performance.

The copper base of the NH-D15 G2 does not come pre-coated with thermal paste. The package includes a NOCTUA NT-H2 thermal paste, weighing about 3.5g, which uses a new metal oxide particle formula. The thermal conductivity is unknown, but it can be applied approximately 3 to 4 times. This thermal paste is sold on e-commerce websites for 139 yuan, which is not a low price.

Support for current mainstream and Intel's next-generation platforms

The NH-D15 G2 is compatible with AMD AM5/AM4 and Intel LGA1851/LGA1700/LGA1200/LGA115x platforms. It can be seen that, in addition to being suitable for current mainstream platforms, it also supports Intel's next-generation LGA1851 platform. Even if a new platform processor is subsequently replaced, it can still be used. We conducted an installation experience on the platform with the Core i7-14700K processor, ROG Z790 DARK HERO motherboard, Galaxy HOF EXTREME D5-7200 memory, and NVIDIA GeForce RTX 4090 D graphics card. Since it is an LGA1700 platform, the standard version of the NH-D15 G2 that we experienced can reduce the pressure on the ILM for the processor by pairing it with a 1mm thick NM-ISW1 pad, so we first installed the pad. It should be noted that, like the ROG Z790 DARK HERO motherboard we used, which is relatively thick, adding a pad will cause the original screws to be unable to tighten. If this situation occurs, it is necessary to contact NOCTUA after-sales service for replacement with longer screws.

When installing the mounting kit, you need to first secure the base plate and the mounting kit. Especially when installing the base plate, you need to lift it with your hand along with the motherboard, then put on the rubber pad, and then use screws to fix the mounting kit. After the mounting kit is fixed, install the heat sink tower and memory, and finally secure the cooling fan.We previously mentioned that the heatsink features a memory slot clearance design on both sides of the tower's bottom, which facilitates users to easily install and remove memory without disassembling the cooler. Additionally, the heatsink's moderate height of 168mm can accommodate mainstream M-ATX and ATX cases. Moreover, the GALAX HOF EXTREME D5-7200 memory I installed, which has a height of 48mm, requires the fan height to be adjusted upwards. After adjustment, the fans will protrude approximately 24mm above the tower.

It can push the 14700K to a staggering power consumption of over 300W at its peak.

NOCTUA is quite distinctive in the field of cooling solutions; it does not have what is commonly referred to as "thermal power" or "heat dissipation power." Instead, it has its own standardized assessment system for cooling performance, which it officially calls the NSPR. We will not delve into this assessment system here, but interested readers can visit the official website () for more information. Currently, the NH-D15 G2 has an NSPR value of 228, which is higher than the previous flagship NH-D15's value of 183. So, how does its performance fare? We will test it next. I reset the motherboard to default settings and used AIDA64 System Stability Test to perform a single-burn FPU test on the processor for over 30 minutes. It can be observed that the processor's power consumption is approximately 275.3W, with the processor's package temperature at 99℃ (ambient temperature at 27℃). The processor experienced thermal throttling, with the performance cores oscillating between 5.3GHz and 5.4GHz, and the voltage fluctuating between 1.24V and 1.25V.

After lifting the processor's temperature restrictions, how much performance improvement can the NOCTUA NH-D15 G2 bring to the Core i7-14700K? To explore this question, I conducted another single-burn FPU test with AIDA64 System Stability Test for over 30 minutes after unlocking the processor's temperature limits. Concurrently, I used HWiNFO software to monitor the real-time changes in temperature and power consumption.

The test results showed that, in the unlocked state, the processor's voltage was 1.3V, and the performance core's turbo frequency reached 5.5GHz. During the test, I noticed that the processor's power consumption soared to a peak of 308W but eventually stabilized at 305.3W. Additionally, through observation with HWiNFO software, the highest package temperature of the processor's performance core stabilized at approximately 106℃.

Moreover, unlike other coolers that "roar" when the fan speed is maxed out under high load, the NH-D15 G2表现得非常"淡定", and there was no particularly noticeable fan noise. I monitored the fan speeds with FanControl software, which were approximately 1535.8RPM and 1475.4RPM for the two fans, almost matching the official data. I measured its noise level with a decibel meter at a distance of about 30cm from the fan, and with an ambient noise of about 45dB(A), the fan noise was approximately 49dB(A), which is about 5dB(A) lower than many air coolers. Especially since our test was conducted in an open platform, if it were installed in a case with a longer distance, the fan noise would be even lower, and during gaming, it would be completely overshadowed by the noise of the graphics card fans. Therefore, there is no need to worry about the noise of the NH-D15 G2, as the "cat fan" has long been recognized for its strength in the industry.In conclusion, the NOCTUA NH-D15 G2 continues to demonstrate its exceptional performance, even without unlocking the processor's thermal limits, it can allow the Core i7-14700K to reach a power consumption of 275.4W. Once unlocked, the power consumption can soar to 305.5W. Behind these figures lies its use of 8 heat pipes, higher density and larger area fins, reflow soldering process, and the more powerful NF-A14x25r G2 PWM fans. Notably, its fans only need to run at half the speed of many standard fans to deliver the same or better performance, and most importantly, to provide better noise reduction. This is undoubtedly an ideal choice for players who pursue high-performance cooling and low-noise performance. For everyday use, the NH-D15 G2 can fully meet the cooling needs of 14th generation Core processors with K suffix under high-load scenarios, such as graphic rendering and gaming, and it is even more effortless to suppress the heat of lower power-consuming AMD Ryzen processors. Of course, the price of 1199 yuan is not cheap, but for fans of air cooling, this price will not be a barrier, as the first batch of stock sold out within less than 10 days of hitting the market. Overall, for players who pursue cooling performance and low noise, the NH-D15 G2 can be "blindly chosen".