Noctua NF-A12x25 G2 and NF-A14x25 G2 Review: Quiet Power for Any Build

Review of Noctua’s G2 lineup: NF-A14x25 G2 and NF-A12x25 G2 fans, NT-H2 paste, and NA-FH1 hub with focus on design, acoustics, pressure, and value.

Noctua has built its reputation on refining the art of quiet, highly-efficient cooling, and the company’s new NF-A12x25 G2 fan is the latest proof of that philosophy. As the second-generation successor to the award-winning NF-A12x25, it builds upon an already legendary design with a Sterrox LCP impeller, ultra-tight 0.5mm tip clearance, and refinements such as Progressive-Bend blades with winglets, Flow Acceleration Channels, and a new Centrifugal Turbulator Hub. The result is a flagship 120mm fan capable of excelling in everything from airflow-oriented case cooling to high-static-pressure scenarios, such as heatsinks and radiators.

While the A12x25 G2 is the newest addition to the lineup, Noctua sent us the larger NF-A14x25 G2 PWM and NF-A14x25r G2 PWM variants to test on the NH-U14S TR5-SP6 cooler, a heatsink designed specifically for AMD’s Threadripper and EPYC platforms. To round out the package, they also included NT-H2 thermal paste, NA-SCW1 cleaning wipes, and a NA-FH1 fan hub, ensuring we had everything needed for a proper installation and evaluation in an actual HEDT environment.

At the time of this review, the two-pack version of the Noctua NF-A14x25 G2 and NF-A14x25r G2 is priced at $84.95 on Amazon (affiliate link), positioning it as a premium cooling solution for enthusiasts and professionals who demand both performance and acoustics in high-power builds.

Specifications NF-A14x25 G2 series fans

A side-by-side comparison of the NF-A14x25 G2 PWM and NF-A14x25r G2 PWM 140mm fans.

Build and Design NF-A14x25 G2 fans

The NF-A14x25 G2 series represents Noctua’s most advanced take yet on the 140mm form factor, carrying forward the engineering refinements first seen in the NF-A12x25 while succeeding the original NF-A14. Both the standard NF-A14x25 G2 PWM and the square-mount NF-A14x25r G2 PWM share the same premium construction and feel, with differences primarily stemming from mounting compatibility.

At the heart of both fans is Noctua’s Sterrox liquid-crystal polymer (LCP) build, a material choice that enables extremely low blade deformation and tight tolerances. The Progressive-Bend impeller design, complete with winglets, Flow Acceleration Channels, and a Centrifugal Turbulator hub, works in tandem with a remarkably tight 0.7mm tip clearance to maximize airflow efficiency while minimizing turbulence and noise. This balance enables the A14x25 G2 to excel in both airflow-intensive applications, such as case cooling, and static pressure environments, including heatsinks and radiators.

To improve radiator performance, the fans include Noctua’s NA-AVG2-LR anti-vibration gasket, ensuring a firm seal and reducing energy loss around the edges. For more challenging intake scenarios, they can also be paired with the optional NA-IS1-14 inlet spacer, which optimizes suction acoustics and airflow. The AAO (Advanced Acoustic Optimisation) frame further refines airflow guidance and vibration damping.

The G2 series also benefits from Noctua’s updated etaPERF motor system with Smooth Commutation Drive 2, engineered for low energy loss and near-silent operation. The addition of SupraTorque technology provides extra torque headroom under back pressure, ensuring the fans maintain their target speed even when mounted on dense heatsinks or radiators, a critical upgrade for high-TDP platforms.

Each fan operates at up to 1500 RPM, and Noctua includes a Low-Noise Adaptor (L.N.A.) that reduces maximum speed to 1250 RPM for quieter operation. At full speed, the fans draw a modest 2.28W and produce just 24.8 dB(A). The L.N.A. further reduces power and acoustics, lowering noise to an impressively quiet 19.7 dB(A).

The accessory bundle includes a 30cm extension cable, a 4-pin Y-cable for connecting a second fan to the same PWM header, four standard fan screws, and four NA-AV2 anti-vibration mounts to minimize vibration transfer. As expected, the fans utilize Noctua’s proven SSO2 bearing, which boasts a rated lifespan of over 150,000 hours and a 6-year warranty.

The distinction between the two models lies in their mounting:

• The NF-A14x25 G2 PWM features the standard 124.5 × 124.5 mm hole spacing, making it compatible with traditional 140mm mounts.
• The NF-A14x25r G2 PWM features a 105 × 105 mm square-frame spacing, enabling it to fit on 120mm-class radiators while maintaining the airflow and acoustics of a 140mm design.

Noctua provided a dual pack of NF-A14x25r G2 PWM and three dual packs of NF-A14x25 G2 PWM for testing, totaling eight fans, which gave us plenty of headroom to evaluate both mounting formats in a fully air-cooled setup. For this, we used the Fractal Design North XL case as our test platform.

NH-U14S TR5-SP6 Heatsink

To handle the extreme thermal demands of modern HEDT platforms, Noctua sent over their NH-U14S TR5-SP6, a premium air cooler specifically designed for AMD’s sTR5 and SP6 sockets. Based on the proven TR4-SP3 design, this revision features a massive heatsink with full IHS coverage. It typically comes paired with two PWM-controlled NF-A15 140mm fans, delivering strong performance without compromising acoustics. For this review, however, we swapped out the bundled NF-A15s for the newer NF-A14x25r G2 PWM fans to evaluate Noctua’s latest engineering on a high-TDP platform. Noctua pre-applies NT-H2 thermal paste out of the box and includes their updated SecuFirm mounting system, rated for the increased pressure specifications of the latest Threadripper and EPYC AMD platforms. Altogether, it’s a purpose-built solution for quietly cooling CPUs with TDPs exceeding 350W.

NA-FH1 Fan Hub

To simplify fan management, Noctua also included the NA-FH1, an 8-channel PWM hub that can power and control up to eight fans from a single header. It supports 12V and 5V fans, including 4-pin PWM and 3-pin voltage-controlled models, making it highly flexible for PC and industrial use. The hub can be powered by SATA (up to 54W) or via the 4-pin PWM input (up to 24W), both of which are protected by self-resetting fuses. A thoughtful touch is the magnetic mount, which makes installation in a case quick and tool-free, while status LEDs allow easy monitoring. In our HEDT build, we utilized the NA-FH1 to connect all eight fans, maintaining synchronization under a single control point.

NT-H2 Thermal Paste

The included NT-H2 thermal compound is Noctua’s second-generation hybrid formula, designed for improved heat transfer over the previous NT-H1 formula while maintaining the same ease of application and long-term stability. An optimized micro-particle composition enables NT-H2 to consistently deliver excellent performance across air and liquid cooling setups, making it suitable for a wide range of applications, from overclocking to quiet builds. It’s also bundled with several cleaning wipes for simple removal when reapplying. During our testing, we removed the stock pre-applied paste from the NH-U14S TR5-SP6 and replaced it with NT-H2 for consistency across our evaluation.

NA-SCW1 Cleaning Wipes

Rounding out the accessory kit, Noctua supplied a 20-pack of NA-SCW1 cleaning wipes. Each wipe is individually packaged, pre-moistened, and large enough to clean both the CPU and heatsink surface in one pass. They’re designed for quick, efficient removal of pastes like NT-H1 and NT-H2, making them a practical addition for enthusiasts who frequently swap or test cooling hardware.

Performance Testing Noctua Cooling Solution

To evaluate the Noctua NF-A14x25 G2 series, we configured the system to ensure consistent airflow and acoustics under a controlled environment. Both NF-A14x25r G2 PWM fans were connected directly to the hub without Low-Noise Adapters (LNA), running at their full 1500 RPM speed. The six case fans were equipped with LNAs, operating at 1250 RPM. Under this configuration, ambient noise levels measured approximately 53-56 dB from a distance of 4 ft (1.2 m) in a standard open-air setup.

HEDT Test Platform

• Motherboard: ASUS Pro WS TRX50-SAGE WIFI
• CPU: AMD Ryzen Threadripper 7970X 32-Core
• RAM: 128GB DDR5 6400MT/s
• Ambient Temperature range: 25-26.5 °C

All tests were performed at maximum fan speed profiles to capture thermal and acoustic characteristics under full load.

Idle Thermal and Power Observations

To establish a consistent thermal baseline, the system was left running idle for several hours with all monitoring tools active. During this period, the AMD Ryzen Threadripper 7970X (32-core) exhibited stable temperature and power characteristics, confirming the reliability of the cooling setup and fan configuration.

The CPU package temperature ranged from 53.6 °C (minimum) to 63.6 °C (maximum), while the individual CCDs maintained values between 39 °C and 55 °C. CCD #0 showed a brief peak of 73.9 °C, likely due to transient polling or sensor spikes rather than a sustained load. The core temperatures were well-balanced, idling between 43.4 °C and 48.5 °C across all cores.

The idle power draw remained consistent over time, with package power fluctuating between 115 W and 129 W, typical for a 32-core Threadripper that maintains active memory and background controller states. Core power varied between 7 W and 36 W, reflecting momentary boosting when background processes engaged.

Y-cruncher (all cores)

y-cruncher is a multithreaded, scalable program that can compute Pi and other mathematical constants to trillions of digits. Since its launch in 2009, it has become a popular benchmarking and stress-testing application for overclockers and hardware enthusiasts.

To evaluate sustained thermal behavior, we used y-cruncher v0.8.6 to thoroughly saturate the AMD Ryzen Threadripper 7970X (32-core) at 100% utilization. This benchmark is a reliable real-world stress test that heavily exercises the compute and memory subsystems. With a TDP of 350W, this test demonstrates how the cooling solution handles prolonged, high-demand workloads.

The workload was configured to calculate 25 billion digits of π, resulting in a total computation time of 310.079 seconds, or approximately 5 minutes and 17 seconds. Throughout the run, the CPU maintained a stable all-core frequency of around 5.07 GHz, with multi-core efficiency measured at 46%.

During the test, the CPU package temperature peaked at 89°C, while the individual CCD temperatures ranged from 81°C to 87 °C. The core maximum reached approximately 85 °C, with no thermal throttling or instability observed. The package power draw peaked at 350 W during the entire test duration, placing it within the maximum rated TDP.

This sustained load demonstrates the Noctua NF-A14x25 G2 cooling configuration’s effectiveness in managing thermal output during extended computational workloads, maintaining high performance while keeping the system acoustically controlled and thermally stable.

Cinebench 2024 (Multi Core)

The Cinebench R24 benchmark tool evaluates a system’s CPU performance by rendering a complex 3D scene using the Cinema 4D engine. It measures single-core and multi-core performance, providing a comprehensive view of the CPU’s capabilities in handling 3D rendering tasks.

For additional thermal and workload evaluation, we ran the Cinebench 2024 Multi-Core benchmark to observe performance and temperature behavior during a sustained 3D rendering workload. This test fully exercises all cores and threads, simulating real-world CPU-bound rendering tasks common in professional workloads.

The AMD Ryzen Threadripper 7970X (32-core) scored 3,403 points, leading the ranking and demonstrating strong multithreaded efficiency. During the run (approximately 10 Minutes), HWMonitor reported a CPU package temperature peak of 89 °C, with core temperatures ranging between 84 °C and 89 °C across the CCDs. The power draw is again aligned with the rated 350W TDP, exhibiting consistent behavior similar to previous stress tests.

Conclusion

Noctua’s NF-A14x25 G2 fans reaffirm the company’s engineering of precision cooling and acoustic excellence. When paired with the NH-U14S TR5-SP6 cooler, NT-H2 thermal compound, and NA-FH1 fan hub, they form a complete, finely tuned ecosystem capable of managing the immense thermal demands of a 350W+ Threadripper platform without throttling or instability. The system maintained full performance under sustained workloads while remaining exceptionally quiet, showcasing how well Noctua’s design philosophy translates to real-world results.

Each component in this setup complements the other, from the advanced impeller design and anti-vibration gaskets to the high-efficiency hub and premium thermal interface. The result is a cohesive, high-performance cooling solution that demonstrates how air cooling can still compete with liquid systems when executed with engineering precision.

At $84.95 for a two-pack, the NF-A14x25 G2 and NF-A14x25r G2 are undeniably premium. Still, their acoustic performance, build quality, and six-year warranty justify the investment for enthusiasts and professionals who prioritize silence and reliability. Together, these products represent the hard work of Noctua’s innovation, providing a unified solution for those seeking maximum cooling efficiency in high-power desktop and workstation environments.

NH-U14S TR5-SP6 Cooler Product page

NF-A14x25-G2 Sx2 Product Page

NF-A14x25r-G2 Sx2 Product Page

NT-H2 Thermal Compound Product Page

NA-SCW1 cleaning wipes Product Page

NA-FH1 Fan Hub Product Page

Engage with StorageReview

Newsletter | YouTube | Podcast iTunes/Spotify | Instagram | Twitter | TikTok | RSS Feed