heading

Featuring advanced aerodynamic design measures such as Flow Acceleration Channels and Noctua’s AAO frame, the NF-A6x25 is a highly optimised, premium quality quiet fan in 60x25mm size. The PWM version sports Noctua’s custom designed NE-FD1 IC for fully automatic speed control via 4-pin fan headers and comes with a Low-Noise-Adaptor to reduce the maximum speed during PWM control from 3000 to 2100rpm. Its superb running smoothness, SSO2 bearing and Noctua’s trusted premium quality make it an elite choice for the highest demands.
Details
Reduced motor hub size

Reduced motor hub size

Thanks to its streamlined, compact motor design, the NF-A6x25's motor hub is smaller than with conventional 6cm fans. This allows for more blade surface area and thus contributes to the NF-A6x25's superior airflow and pressure performance.
Flow Acceleration Channels

Flow Acceleration Channels

The NF-A6x25 impeller features suction side Flow Acceleration Channels. By speeding up the airflow at the crucial outer blade regions, this measure reduces suction side flow separation and thus leads to better efficiency and lower vortex noise.
AAO frame

AAO frame

Noctua's AAO (Advanced Acoustic Optimisation) frames feature integrated anti-vibration pads as well as Noctua's proprietary Stepped Inlet Design and Inner Surface Microstructures, both of which further refine the fan's performance/noise efficiency.
Stepped Inlet Design

Stepped Inlet Design

Noctua's Stepped Inlet Design adds turbulence to the influx in order to facilitate the transition from laminar flow to turbulent flow, which reduces tonal intake noise, improves flow attachment and increases suction capacity, especially in space-restricted environments.
Inner Surface Microstructures

Inner Surface Microstructures

With the tips of the fan blades ploughing through the boundary layer created by the Inner Surface Microstructures, flow separation from the suction side of the blades is significantly suppressed, which results in reduced blade passing noise and improved airflow and pressure efficiency.
Integrated Anti-Vibration Pads

Integrated Anti-Vibration Pads

Integrated Anti-Vibration Pads made from extra-soft silicone minimise the transmission of minute vibrations while maintaining full compatibility with all standard mounting systems and fan clips used on heatsinks.
SSO2 bearing

SSO2 bearing

The NF-A6x25 features the further optimised second generation of Noctua's renowned, time-tested SSO bearing. With SSO2, the rear magnet is placed closer to the axis to provide even better stabilisation, precision and durability.
Custom-designed PWM IC with SCD

Custom-designed PWM IC with SCD

Supporting fully automatic PWM speed control, the NF-A6x25 PWM uses Noctua's custom-designed NE-FD1 PWM IC that integrates Smooth Commutation Drive (SCD) technology. By providing smoother torque impulses, SCD suppresses PWM switching noises and thus makes the fan quieter at low speeds.
Low-Noise Adaptor

Low-Noise Adaptor

The NF-A6x25 PWM is supplied with a (L.N.A.) that reduces the maximum fan speed from 3000 to 2100rpm. The L.N.A. can be used either to run the fan at a fixed speed of 2100rpm or to cap the maximum speed when using automatic PWM control.
Extensive cabling options

Extensive cabling options

The fan's short 20cm primary cable minimises cable clutter in typical applications while the supplied 30cm extension provides extended reach when necessary. Both cables are fully sleeved and a 4-pin y-cable allows the connection of a second NF-A6x25 PWM fan to the same PWM fan header for automatic control.
6-year manufacturer’s warranty

6-year manufacturer’s warranty

Noctua fans are renowned for their impeccable quality and outstanding longevity. Like all Noctua fans, the NF-A6x25 features an MTTF of more than 150.000 hours rating and comes with a full 6-year manufacturer’s warranty.
NF-A6x25 PWM
FAN Specification
Size
60x60x25 mm
Mounting hole spacing
50x50 mm
Connector
4-pin PWM
Bearing
Blade Geometry
Rotational Speed (+/- 10%)
3000 RPM
Rotational Speed with L.N.A. (+/- 10%)
2100 RPM
Min. Rotational Speed (PWM, +/-20%)
550 RPM
Acoustical Noise
19,3 dB(A)
Acoustical Noise with L.N.A.
13,7 dB(A)
Static Pressure
2,18 mm H₂O
Static Pressure with L.N.A.
1,29 mm H₂O
Max. Input Power
0,96 W
Max. Input Current
0,08 A
Voltage
12 V
MTTF
> 150.000 h
Scope of delivery
  • Low-Noise Adaptor (L.N.A.)
  • 4-Pin Y-Cable
  • 30cm Extension Cable
  • 4 Vibration-Compensators
  • 4 Fan Screws
Warranty
6 years
NF-A6x25 PWM
NF-A6x25 PWM Video
A-Series fans
08.11.2015 // AndroidPC.es
test.gif

NF-A6x25 PWM Review

Después de probar los modelos NF-A6x25 PWM, NF-A6x25 FLX, NF-A4x10 FLX y NF-A4x10 5V nos dan ganas de dejar un ventilador en nuestras placas pasivas, pero preferimos no hacerlo, como ya sabéis nos gustan los sistemas pasivos. Ciertamente es estos productos pueden ofrecen una mejora térmica en nuestros dispositivos si vamos a exprimirlos y además no nos molestan con ruidos. Si tenemos algún modelo pasivo con problemas térmicos añadirle un pequeño ventilador bien dimensionado siempre es una solución, sobretodo si tienen la calidad de estos modelos.
Test verdict: "Los recomendamos sin ninguna duda para quien quiera mejorar el rendimiento de su miniPC o AndroidPC con problemas térmicos." (Joaquin Prida Trujillo, AndroidPC.es)
15.04.2015 // ByTheWay.gr
test.gif

NF-A6x25 PWM Review

Κλείνοντας,οι επιδόσεις του νέου NF-A6x25 PWM είναι εξαιρετικές. Καταφέρνει να έχει σπουδαίες επιδόσεις και εξαιρετικά επίπεδα θορύβου με τον low noise adapter που προσφέρει η εταιρία. Set it and forget it προσέγγιση και μπορούμε να εγγυηθούμε το "forget it" κομμάτι. Η επιμονή στην λεπτομέρεια της Noctua είναι προφανής. Μερικές από τις αναφερόμενες τεχνολογίες θυμίζουν μελέτες αεροδυναμιστών παρά κατασκευαστών computer parts και η παρεχόμενη εγγύηση των 6 ετών είναι χωρίς προηγούμενο σε μια αγορά που η 3ετής πλέον θεωρείται πολυτέλεια. Σκεφτείτε το, το 2020 οι ανεμιστήρες σας θα είναι ακόμα εντός εγγύησης και μάλιστα από μια εταιρία που συνηθίζει να την τιμά, χωρίς αστείες δικαιολογίες.
Test verdict: "Η Noctua δείχνει ότι δεν αγχώνεται να διώξει το premium χαρακτήρα της ούτε από την τιμολογιακή της πολιτική, και ειλικρινά δεν περιμέναμε κάτι διαφορετικό εκεί. Όμως, αυτό που έχουμε να παρατηρήσουμε είναι η κορυφαία ποιότητα κατασκευής σε συνδυασμό με τον εξαιρετικό σχεδιασμό που επιφέρουν καλύτερες επιδόσεις, ενώ ταυτόχρονα μπορούν και προσφέρουν ήσυχη και απρόσκοπτη λειτουργία ακόμα και σε πολύωρη χρήση." (Nasioulis Evangelos, ByTheWay.gr)

Installation Manual (PDF)

Information Sheet (PDF)

Can I use Low-Noise Adaptors with y-cables / multiple fans?

Yes, Low-Noise Adaptors (L.N.A.s) can be used with y-cables, but please make sure to use one L.N.A. per fan and to place the L.N.A.s between the y-cable and the fans as shown below. Never use one L.N.A. for two (or more fans) by placing it between the mainboard and the y-cable!

D15S

Can I use Noctua fans in my system from Acer, Apple, Dell, HP, Lenovo or other major brands?

Noctua 12V fans comply with the established specifications for standard PC systems issued by Intel and AMD. Systems from Acer, Apple, Dell, HP, Lenovo or other major brands often deviate from these specifications e.g. by using proprietary fan headers, custom pin-alignments or pin-configurations, different methods of fan speed control, etc. This can lead to compatibility issues when using Noctua fans in systems from said brands. Some of these problems can be avoided with some technical knowledge, but especially BIOS related issues (e.g. errors or shutdowns due to low fan speed) can often not be resolved. As a result, Noctua does not officially support systems from Acer, Apple, Dell, HP, Lenovo or other major brands.

Can Noctua fans be used to replace noisy stock fans in NAS devices?

Noctua fans such as the 40, 60, 80 or 92mm NF-A series models are ideal for replacing noisy stock fans in NAS devices in order to make them quieter and thousands of users have managed to significantly reduce the noise levels of their NAS units this way. However, while it is easy and straightforward to replace the fans in some cases, it can be very difficult in others, so Noctua strongly recommends that users carefully research if it is possible to easily replace the fan(s) of their NAS device before purchasing a Noctua fan for this purpose. Some of the common issues that can occur when replacing NAS fans are:

  • Different pin assignment: Whereas Noctua fans use the standardised pin assignment for PC fans (see this FAQ for details), some NAS units use different assignments. For example, some devices have the power and GND or rpm and PWM pins swapped. Therefore please carefully verify that your NAS device uses the same pin assignment as standard fans. Experienced users may also change the pin assignment by cutting and resoldering the fan cables, but please note that this will void your Noctua manufacturer’s warranty.
  • Different pin functions: Noctua fans use the standardised pin functions for PC fans (see this FAQ for details); however, some NAS units use fans where certain pins serve a different function. For example, some devices use the RPM pin for “power good” signals. Therefore please carefully verify that your NAS device uses the same pin functions.
  • Firmware speed control: Some NAS devices demand a certain maximum or minimum fan speed. If the new fan doesn’t have the same or similar maximum or minimum speed, the device may display errors or even shut down.
  • Different starting voltage: Most NAS devices use voltage-based speed control. If the new fan has a higher starting voltage than the original fan, it may not start up right away. This may lead the NAS device to display errors or even shut down because it suspects a fan failure.
  • Different power draw: Some NAS devices monitor the fan’s power draw. If the new fan has a lower power consumption than the stock fan, the device might display errors or even shut down.

Please note that most NAS manufacturers don’t provide detailed documentation regarding fan compatibility and control, so users who want to replace the fans of their devices usually have to rely on “How to” guides, blog and forum posts or video tutorials. For example, there are excellent video tutorials available for changing the fans in popular Synology NAS models (DS416j, DS1515+ and DS1812+ in English, DS416/DS415/DS916/DS216/DS214 and DS1515+ in German). Please also note that fan compatibility and control can vary from model to model and even from revision to revision even if the devices stem from the same manufacturer. As a result, it is important to make sure that the information or guidelines you rely on when replacing your NAS fan are applicable to your specific model as well as your specific hardware and firmware revision.

Due to the possible issues listed above, Noctua recommends that only experienced users attempt to replace their NAS fans. Please note that since there are so many different NAS models and most of them lack documentation for aspects such as fan compatibility and control, Noctua customer support cannot assist you with compatibility issues when replacing NAS fans. Please contact your NAS manufacturer for any questions regarding aspects such as the device’s pin alignment or fan monitoring and control.

Which Noctua fan or CPU cooler should I buy? How to choose the right model?

Not sure which Noctua product to buy? Our detailed buying guides for fans and CPU coolers help you to choose the model that works best for you.

How can I check if my 4-pin fan header supports PWM?

Some mainboards feature 4-pin fan headers that actually don‘t use a PWM signal on Pin 4 to control the fan speed but rather reduce the voltage on Pin 2 (like a standard 3-pin fan header). As the fan speed at minimum voltage is usually higher than the speed at 20% PWM duty cycle, the fan can not reach as low minimum speeds under voltage control as under PWM control. Please refer to your mainboard manual to check whether or not your mainboard has 4-pin fan headers that control the fan speed by reducing voltage on Pin 2 rather than by changing the PWM duty cycle on Pin 4:

4 pin fan header types

Note that mainboard manufacturers use different terms to indicate that Pin 4 is not being used for PWM control (e.g. “+5V”, “VCC” or “NC”), but if one of these terms is used, you can be sure that the fan header does not support PWM. If Pin 4 is described as “Speed Control” or “PWM” or the like, you can be sure that the fan header supports PWM.

Unfortunately, the description of Pin 2 is not always a clear indication as some manufacturers use terms such as “Fan PWR” or “Power” for both types of fan headers. However, if Pin 2 is described as “Speed Control”, you can also be sure that the fan header does not support PWM based speed control. If Pin 2 is described as “+12V”, this is a clear indication that the fan header supports PWM.

Please also note that in some cases, the descriptions of the pin layouts in the mainboard manuals may not be correct and some models actually allow you to switch the fan headers from voltage control mode to PWM control mode in the BIOS even though the pin descriptions do not indicate PWM support. We thus recommend to look for these options in the BIOS before taking other measures. In case of doubt, please contact your mainboard manufacturer.


If your mainboard features other 4-pin fan headers that use PWM for speed control, you can run multiple fans from these headers using Y-split cables. Make sure not to exceed the specified maximum power draw of the fan headers (usually 10-12W) though.

I'm experiencing fan speed issues with my motherboard from Supermicro, what can I do?

The BIOS of many motherboard models from Supermicro expects a certain minimum fan speed (usually 700rpm), which is higher than the minimum fan speed that can be achieved with Noctua's PWM fan models. The BIOS may interpret the low minimum RPM of Noctua fans as a fan error and thus try to run the fan at 100% for a short period before going back to automatic control.. This can result in oscillating fan speeds and fan speed warnings in the BIOS or the fan management console.

Unfortunately there is usually no option to set a lower minimum value that would suit the low minimum speed of Noctua PWM fans.The issue can thus only be resolved by either disabling automatic fan speed control in BIOS, which will cause the fans to run at a constant speed, or by requesting a modified BIOS file from Supermicro, which takes the minimum fan speed of Noctua fans into account (charges might apply).

How should I clean my Noctua fan?

Fans inside computer cases tend to accumulate dust over longer periods of usage. In order to maintain maximum performance, please clean your fans regularly using a duster, slightly moist tissue or canned air. Please be careful not to use too much force in order to prevent any damage to the fan. Please do not use a vacuum cleaner as this may apply excessive force to the fan and do not put the fan under running water as water residues inside the motor may lead to short circuits.
In order to ensure flawless operation over many years of usage, Noctua’s premium grade SSO bearings are fully sealed to prevent the entering of fine dust particles. Please note that the fan is not designed to be taken apart by the user. Removing the impeller from the frame will break the sealing of the bearing and results in a loss of warranty.

What pin configuration do Noctua 12V fans use?

All Noctua fans feature the standard pin-configurations set out in the Intel and AMD specifications. These standard pin-configurations are used on most mainboards and fan controllers today:

pin configuration

Can I run 4-pin PWM fans on 3-pin fan headers?

PWM fans come with a 4-pin connectors for fully automatic speed control via your mainboard’s 4-pin PWM fan headers. Please note that 4-pin fans can also be connected to your mainboard’s 3-pin fan headers though. When connected to 3-pin fan headers, the fan will run at full speed (unless the mainboard supports voltage based speed control).

Can I disassemble my fan for cleaning (or other purposes, e.g. painting)?

In order to ensure flawless operation over many years of usage, all Noctua fans come with a premium grade SSO bearing, which is fully sealed to prevent the entering of fine dust particles. Please note that the fan is not designed to be taken apart by the user. Removing the impeller from the frame will break the sealing of the bearing and results in a loss of warranty.

It is thus recommended to clean your fans using a duster, slightly moist tissue or canned air. Please be careful not to use too much force in order to prevent any damage to the fan. Please don’t use a vacuum cleaner as this may apply excessive force to the fan.

Can Noctua fans be used to replace noisy stock fans in switches, routers or other network devices?

Noctua fans such as the 40, 60, 80 or 92mm NF-A series models are ideal for replacing noisy stock fans in switches, routers and other network devices in order to make them quieter and thousands of users have managed to significantly reduce the noise levels of their units this way. However, while it is easy and straightforward to replace the fans in some cases, it can be very difficult in others, so Noctua strongly recommends that users carefully research if it is possible to easily replace the fan(s) of their network device before purchasing a Noctua fan for this purpose. Some of the common issues that can occur when replacing pre-installed fans are:

  • Different pin assignment: Whereas Noctua fans use the standardised pin assignment for PC fans (see this FAQ for details), some network devices use different assignments. For example, some devices have the power and GND or rpm and PWM pins swapped. Therefore please carefully verify that your device uses the same pin assignment as standard fans. Experienced users may also change the pin assignment by cutting and resoldering the fan cables, but please note that this will void your Noctua manufacturer’s warranty.
  • Different pin functions: Noctua fans use the standardised pin functions for PC fans (see this FAQ for details); however, some network devices use fans where certain pins serve a different function. For example, some devices use the RPM pin for “power good” signals. Therefore please carefully verify that your device uses the same pin functions.
  • Firmware speed control: Some network devices demand a certain maximum or minimum fan speed. If the new fan doesn’t have the same or similar maximum or minimum speed, the device may display errors or even shut down.
  • Different starting voltage: Most network devices use voltage-based speed control. If the new fan has a higher starting voltage than the original fan, it may not start up right away. This may lead the device to display errors or even shut down because it suspects a fan failure.
  • Different power draw: Some network devices monitor the fan’s power draw. If the new fan has a lower power consumption than the stock fan, the device might display errors or even shut down.

Please note that most network device manufacturers don’t provide detailed documentation regarding fan compatibility and control, so users who want to replace the fans of their devices usually have to rely on “How to” guides, blog and forum posts or video tutorials. Please also note that fan compatibility and control can vary from model to model and even from revision to revision even if the devices stem from the same manufacturer. As a result, it is important to make sure that the information or guidelines you rely on when replacing your fans are applicable to your specific model as well as your specific hardware and firmware revision.

Due to the possible issues listed above, Noctua recommends that only experienced users attempt to replace their pre-installed fans in network devices. Please note that since there are so many different devices and most of them lack documentation for aspects such as fan compatibility and control, Noctua customer support cannot assist you with compatibility issues when replacing pre-installed fans. Please contact your network device manufacturer for any questions regarding aspects such as the device’s pin alignment or fan monitoring and control.

Do you have a question concerning one of our products? Please use this form to pose a question!