Noctua NF-A12x25 PWM G2 Fans Review

After releasing the next generation of 140mm fans i.e NF-A14x25 G2 PWM, Noctua has released NF-A12x25 G2 PWM fans. These fans rest on the footprint of legendary NF-A12x25 PWM. The NF-A12x25 PWM fans hold a remarkable note in terms of design concept, materials used for construction, and tip clearance, all of which played a leading role towards high performance.

Noctua aims at the mid-section of the P/Q chart, i.e, trying to achieve the best optimal combination of air flow and air pressure. The NF-F12 fans favor the air pressure applications in particular and not all scenarios require such applications. The fan sitting in the mid-section provides a good all-around performance for your particular PC related cooling requirement. This was made possible with NF-A12x25 PWM fans. We can expect better performance from NF-A12x25 G2 PWM fans, which we shall see in the testing section.

These fans are available in 3 options:

• NF-A12x25 G2 PWM Single Fan Pack costing USD 34.90
• NF-A12x25 G2 LS-PWM Single Fan Pack costing USD 34.90
• NF-A12x25 G2 PWM Sx2-PP Two Fans Pack costing USD 64.90

The LS-PWM is a low-speed edition of the regular NF-A12x25 G2 PWM fan, making it suitable for case ventilation in particular. Other than that, it has the same design as the regular G2 fans. The S-2xPP fans come with two NF-A12x25 G2 PWM fans operating in offset speed to reduce harmonic phenomena like intermittent vibration or humming coming from interference. This offset is ±50 RPM.

I am testing NF-A12x25 G2 PWM fans in this content and will be testing these against the NF-A12x25 PWM and be quiet! Silent Wings 4 fans.

Specifications

Packaging and Contents

The fans are shipped inside cardboard-based packing boxes. Noctua has changed the color theme with the launch of NF-A14x25 G2 PWM fans, and the same theme can be seen on the NF-A12x15 G2 PWM fans.

The Sx2-PP fans come in a large-sized packing box. These fans are placed parallel to each other in this box, and there is an accessory box sandwiched between the fans.

The single fan pack comes with an NF-A12x25 G2 PWM and an accessory box. All editions have standard accessories.

The NF-A12x25 G2 PWM box comes with

• 1x NF-A12x25 G2 PWM fan
• 1x NA-RC7 Low-Noise Adaptor (L.N.A.)
• 1x NA-YC1 4-pin PWM splitter cable
• 1x NA-EC1 30cm extension cable
• 1x NA-AVG1 anti-vibration gasket
• 4x NA-AV2 anti-vibration Mounts
• 4x Fan screws

Closer Look

The new generation NF-A12x25 G2 PWM fans are designed on the building block of NF-A12x25 PWM, hence they carry the same technologies and design as the NF-A12x25 but with further enhancements.

Like I mentioned in the content of NF-A14x25 G2 PWM fans, Noctua did not opt for a new name; instead use G2, showing the second generation of the NF-A12x25 PWM fans. This would also help in the easy identification of the desired fans.

There are plenty of key notes when it comes to the design of NF-A12x25 G2 PWM fans, which is obvious given they follow the design of NF-A12x25 PWM in that sense. Each fan has 9x impellers. They are progressive bend impellers featuring flow acceleration channels and winglets.

These blades are swept backwards close to the hub and progressively bent forward further out. These work in tandem with the centrifugal Turbulator hub to improve the lift and uniform loading across the blade surface.

The winglets are introduced in an attempt to reduce the tip vortices. The NF-A12x25 G2’s winglets are fine-tuned to work with other features of the frame for consistent efficiency.

Noctua has used LCP (Liquid Polymer Crystal) material for the impellers, as we saw on the NF-A12x25 PWM fans. Noctua was the first brand to start using LCP and ultra-low tip clearance, with others following in the same design footprint.

Noctua is using the same AAO (Advanced Acoustic Optimisation) frames that are on the NF-A12x25 PWM fans. These frames use integrated anti-vibration pads, Noctua’s proprietary Stepped Inlet Design, and Inner Surface Microstructures. All these work together to provide the best possible performance and reduce noise output.

These fans come with 4x load-relief anti-vibration pads pre-installed on the front side of the fan. The rear of the fan also comes equipped with these pads, unlike the NF-A14x25 G2 which has a NA-AVG1 silicone gasket installed on the rear of the fan out of the box. However, Noctua has provided this gasket in the accessory box, should you want to use it. This gasket is useful for radiator and surface mounting, providing a tight seal with the fan.

Since the gasket covers the entire border of the fan’s frame, it helps to dampen vibrations and to reduce air loss between the fan and the radiator for optimal cooling performance. The Anti-vibration pads serve a similar purpose.

There is a Noctua branding on one side of the frame.

There are arrow markers providing a direction guide to the user. These show the direction of airflow through the fan and the direction in which the blades spin.

The backside of the fan has an inward slope on the four sides. There is a 4-arm assembly connecting the motor hub with the frame. The fan draws 0.19A at 12VDC using 2.28W of power. The arms are angular, providing directional airflow.

The NF-A12x25 G2 PWM fans use optimized SSO2 bearings in which the rear magnet is placed closer to the axis for stabilization. Noctua has employed a CNC-milled bearing shell made of brass material, providing long-term stability with minimum tolerance.

Noctua has used the NE-FD6 motor drive system in these fans which is combined with the SupraTorque technology. This motor provides better energy efficiency. This motor has a Hall Effect sensor for precise commutation performance. Speaking of commutation, these fans have Noctua’s Smooth Commutation Drive 2 technology. The aim here is to reduce the motor noise to the extent possible.

The SuporaTorque technology allows these fans to maintain the same RPM even when employed on the surface with high back pressure.

You can use the NA-IS1-12 inlet side spacer with the NF-A12x25 G2 to reduce influx turbulences in “pull” type applications where the fan draws air through a grill, mesh filter or perforated panel.

Noctua has managed 0.5mm tip clearance between the blades and the frame. This clearance is 0.7mm on NF-A14x25 G2 PWM fans. This design helps in reducing leak flows through the gap between the blades and frame. This would improve the performance efficiency even with a highly resistant surface.

The functionality of coming to a stop at 0% PWM gives these fans a huge lift for the semi-passive cooling application. In addition, the wider PWM range goes from 360 RPM to 1800 RPM.

Safety Data

These fans come with safety features/protections that include:

• Reverse Polarity Protection
• Over Voltage Protection
• Over Current Protection

These protections make these fans suitable even in challenging electrical environments. You can have peace of mind.

Testing

The following configuration is used for thermal testing:

• AMD Ryzen 9 9900X
• ASRock X870E NOVA WiFi
• GSkill TridentZ NEO RGB 32GB 6400MHz CL30 DDR5 kit
• Be quiet! Silent Loop 3 360 Liquid Cooler
• ASRock Phantom Gaming RX 7600 Graphics Card for Display
• Biwin Black Opal X570 Pro 4TB NVMe SSD
• Be quiet! Straight Power 11 850W Platinum PSU
• Praxis Wetbench

Here is the settings table for testing:

Settings	PBO Enabled [243W]
Clock (MHz)	Auto
Voltage (V)	Auto
Thermal Paste	Noctua NT-H2
Thermal Paste Application	Dots Method
Test Run Time	30 minutes
Idling Time	10 minutes
All Fans Speed	100% PWM Duty Cycle
Pump Speed
Stress Software	CINEBENCH R23.2
Monitoring Software	HWINFO64

I am reporting absolute temperature in the graph because the room temperature was at 26°C throughout the day. The testing is done on an open-air bench system. Once inside the chassis, the temperatures are expected to rise and would largely depend upon the optimal airflow inside the chassis.

We have an incremental thermal performance compared to the NF-A12x25 PWM, but the key difference comes from the acoustic performance. The NF-A12x25 G2 PWM delivers the same performance level as be quiet! Silent Wings 4 120mm fan and slightly better performance over the regular NF-A12x25 PWM, coming in atthe lowest sound level. This is a win for the G2 variant.

Next, the tests were repeated at 37dB(A) noise level. All fans were set to rotate at speeds that would result 37db(A) sound level. This is what we call noise-normalized performance, and this test reveals the true picture of the given cooling solution. The Noctua NF-A12x25 G2 PWM shows its might in this testing.

Conclusion

Noctua is back with another release. This time it is the NF-A12x25 G2 PWM fan taking over the NF-A12x25 PWM fans. The new fans are available in three editions. The two-fan edition named Sx2-PP comes with two NF-A14x25 G2 PWM fans set to operate at an offset speed of ±50 RPM to overcome the humming and turbulence that may come with both fans operating at the same speed. Then there is an LS-PWM version, which is a low-speed variant that you can particularly use for case ventilation. The key benefit of this version is low noise out of the box. The third is a single-fan edition of the regular NF-A12x25 G2 PWM fan. There is no ‘r’ edition, unlike the NF-A14x25 G2 PWM that was released for NH-D15 G2 coolers.

The building block of NF-A14x25 G2 PWM fans is from NF-A12x25 PWM fans but with further enhancements in the design and technologies. These fans still use the same Liquid Polymer Crystal (LPC) material for blades as are on NF-A12x25 PWM fans. Noctua is market leader when it comes to innovation and they showed that with NF-A12x25 PWM fans.

I am not going into the details of the technology and design of these new fans. I am going to list them below. You can read the content for more details and can even find more details on NF-A14x25 G2 PWM product page on the Noctua website:

• AAO (Advanced Acoustic Optimization) Frame
• Stepped Inlet Frame
• Inner Micro Structure
• Sterrox material derived from LCP (Liquid-Crystal Polymer) used on the impeller
• Gap of only 0.5mm between the impeller and the frame
• Additional brass structure to reinforce the axle mount
• CNC milled bearing shell
• Flow Acceleration Channels and Winglets on the blades
• Further Improved SSO2 bearing
• etaPERF Motor with NE-FD6 Motor IC
• Commutation Drive 2 System
• SupraTorque
• PWM Regulation with auto stop function on 0% PWM
• Safety Protections for Challenging Electrical Environments
• 6-Year Warranty
• Low Noise Adapter and Extensive Cabling Options
• Integrated anti-vibration pads and gasket
• Progressive-Bend Impeller
• Centrifugal Turbulator Hub

I was interested to see the generational gap between the NF-A12x25 PWM and NF-A12x25 G2 PWM fans in terms of thermal and noise performance. For comparison, I have included the b quiet! Silent Wings 4 PWM High Performance fans as well. The fans were tested on AMD Ryzen 9 9900X with 243W power.

Our testing is showing that NF-A12x25 G2 PWM fans have roughly 0.8ᵒC better cooling performance and 1.2 dB(A) better sound output compared to the NF-A12x25 PWM fans. This is an incremental performance gain. However, compared to the Silent Wings 4 fans, this is a drastic performance gain with a sound difference of a whopping 4.6 dB(A) for similar performance.

Noctua is back in the 120mm fans segment with NF-A12x25 G2 PWM, providing an incremental improvement over the regular NF-A12x25 PWM fans but a substantial difference compared to the performance in the sound department.

What does it tell you? If you have NF-A12x25 PWM fans, stay with these fans. They are still kicking well. But if you are due for an upgrade in 120mm size fans and sound freak, then grab NF-A12x25 G2 PWM without a doubt. These are best sounding fans on the market, delivering powerful thermal performance at low sound levels.