Noctua NF-S12A ULN, FLX and PWM Fan Reviews



Noctua was established back in 2005 with the aim of designing premium, quiet and quality cooling products. They have become a big brand in the cooling market and most enthusiasts will know the name. Their products to date have always been easily distinguishable thanks to their cream and brown colour scheme.

Today we are checking out the Noctua NF-S12A 120mm fans; they are available in three different variations, the ULN, PWM and FLX. They are Noctua’s third generation of their popular S12 series quiet case fans and feature a large number of unique design features, so let’s see how they fair. We have all three editions of the fans take a look at so without further ado lets crack on.

Noctua NF-S12A 9


Noctua NF-S12A 1





Packaging and accessories

Below you can see the design of the packaging. It is very professional with a matt finish print. Both the front and back of the packaging open out. Inside the front cover there is a window to get a glimpse of the fan and we also see an explanation of how the anti stall knobs feature on the fan work.

Noctua NF-S12A 2

Noctua NF-S12A 4

Around the back of the box we see some of the technical specifications highlighted along with a description of the fan in 8 different languages. On the back inside cover we see a number of features which are used on the NF-S12A highlited with a short description about each.

Noctua NF-S12A 3

Noctua NF-S12A 5

I really like the packaging of the fans which from the outset helps to deliver a premium feel to the product. It is well designed and provides all the information about the product; perfect in a retail environment.

Accessory-wise the different variations of the fan come with different accessories. Below I detail what is included with each model.

Noctua NF-S12A FLX

· 30cm three pin extension cable (NA-EC2)
· Low-Noise Adapter (NA-RC10)
· Low-Noise Adapter (NA-RC12)
· 4:3-pin Adapter (NA-AC1)
· 4 Silver Fan Screws
· 4 Brown soft rubber anti-vibration mounts
· Manual

Noctua NF-S12A 8

Noctua NF-S12A ULN

· 4:3-pin Adapter (NA-AC1)
· Low-Noise Adapter (NA-RC12)
· 30cm three pin extension cable (NA-EC2)
· 4 Silver Fan Screws
· 4 Brown soft rubber anti-vibration mounts
· Manual

Noctua NF-S12A 23

Noctua NF-S12A PWM

· Low-Noise Adapter (NA-RC7)
· Y Splitter cable (NA-YC1)
· PWM extension cable (NA-EC1)
· 4 Silver Fan Screws
· 4 Brown soft rubber anti-vibration mounts
· Manual

Noctua NF-S12A 24

Noctua NF-S12A 7

There are a lot of accessories included with whichever variation you get. Something which is really good to see and is in keeping with the premium product feel.

Closer Look

All of the three different variations of the NF-S12A use the same physical design, with a cream framework and brown fan blades.

Noctua NF-S12A 18

On each corner of the fans are some brown soft anti-vibration silicone corners which feature on both sides allowing you to have the benefit these offer if you are using the fan as an intake or an exhaust. They help to prevent vibrations being passed from the fan into the case and as a result minimise noisy vibration. These pads can be easily removed if needed.

Noctua NF-S12A 15

Looking at the back of the fan there is a sticker over the motor/bearing area which highlights the power specifications of the fan. No matter which model you choose all the models use the SS02 bearing with a metal bearing shell. Noctua say that with the SS02 bearing the rear magnet is placed closer to the axis to provide even better stabilization, precision and durability. The bearing is fully sealed against dust etc. The metal bearing shell that encases the bearing is made from CNC milled brass which delivers a high degree of precision in the manufacturing process and helps to deliver long term stability.

Noctua NF-S12A 13

The fan blades feature the third generation of Noctua’s straight blade design which has been further optimized for even better airflow/noise efficiency. Across the blades are anti-stall knobs which help to reduce flow separation and help the fan to deliver better performance on heatsinks and radiators.

Noctua NF-S12A 19

Around the edge of the fan’s intake is a stepped design; this is only present on the intake side of the fan. Noctua say that this stepped design helps to reduce intake noise, improves flow attachment and increases suction capacity especially in space restricted environments.

Noctua NF-S12A 17

Around the inner rim of the fan’s frame work are little dimples in the plastic. These create a boundary layer and help to prevent flow separation from the suction side of the blades. These dimples result in reduced blade passing noise and improved airflow and pressure efficiency.

Noctua NF-S12A 16

The NF-S12A also features something called Smooth Communication Drive 2 which is the latest edition to Noctua’s advanced Smooth Communication Drive System and Noctua say it ensures superb running smoothness by eliminating torque variations and switching noises.

Noctua NF-S12A 10

The fan is a standard 25mm thickness and the corners of the fan also have an open design, something which is good to see. Noctua are so confident in their fans’ reliability and construction that they offer a 6 year warranty on this fan and has a MTBF (Mean Time Between Failures) of more than 150,000 hours!

Noctua NF-S12A 20

The cable that is fixed to the fan is 20cm long and comes braided in a rubber-like braid, which is really good quality so that you can’t see the cables through it. All of the accessories also come braided which I am also pleased to see and is something that can get overlooked.

Noctua NF-S12A 14

Mounting-wise you can either screw the fan in with case screws or M3 screws etc (not supplied) or you can use the four anti-vibration rubber pins which are supplied. You just push them through your case then pull them through the fan.

Noctua NF-S12A 22

Noctua NF-S12A 12

The PWM edition of the fan uses Noctuas custom designed PWM IC (NE-FD1) that is combined with Smooth Communication drive.

Noctua NF-S12A 25



Noctua NF-S12A 21


At 5v the performance of all the variations across the board was great. They were silent even when putting my ear right up close to the fan. Both the PWM and FLX editions produced more airflow at 5v compared to the ULN edition but were equally as quiet. There was a mild breeze coming from each fan, which was surprisingly good when matched with their noise performance.
I would like to point out though with the ULN edition plugged straight in at 5v, the fan did struggle to get spinning but with a slight tap it was fine. This I suspect is due to the slower overall RPM. Both the PWM and FLX editions didn’t have a problem running at 5v.


At 7v the performance of all the editions was still great. All editions still remained quiet, the FLX and PWM editions did become slightly audible at about 10cm away but any further away from my ear and they were silent. The ULN edition did remaining silent even with my ear close to the fan. There was a nice breeze coming from the fans, with the ULN edition producing less of a breeze which is to be expected since it spins at a slower RPM for the same given voltage. I would be quite happy to use the fans permanently at this setting in my main rig.


At 12v the ULN edition was still silent but producing more airflow than before which is to be expected. Both the FLX and PWM editions did become audible but were noticeably pushing through a lot more air, much more than I was expecting. Their noise performance was also good and although audible, it was far from loud and still much quieter than a lot of fans on the market.

In my opinion 7v would probably be my setting of choice for the FLX and PWM editions as it produced the best noise to performance ratio out of the three voltages. The ULN edition I would personally run at 12v as it was still quiet and heeding good results. All the fans were near silent at both 5v and 7v but with the overall RPM of the ULN edition being slower it remained silent even at 12v. The fans performance was great and obviously, depending on your personal preference, will depend which edition you buy. Even at low speeds the airflow was impressive and at 12v the fans were really moving some air!

The PWM edition of the fan, I feel, combines both the ULN and FLX editions but relies on you having PWM control, with a minimum of 300RPM ranging from 1200RPM; it does offer the benefits of both models.


The Noctua NF-S12As are a premium range of fans and, as such, come with a premium price tag as expected. The long 6 year warranty is testament to the fans’ build quality and durability and is great to see.

The fans are very advanced in their design; it is clear that a lot of work has gone into the different technologies and innovations implemented into the fans. They come well presented with a wealth of accessories, everything you could possibly need.

Silence, performance and quality is key with the design of these fans and it is evident that this has been the focus throughout the design. In my testing I found the fans to perform very well with their acoustic performance being great. If you are focused on complete silence then the ULN model is the one for you. The FLX model delivers better performance and again solid acoustic performance even though it is slightly louder than its ULN relation. I feel the PWM edition combines both qualities of the FLX and ULN and adds PWM functionality.

The build quality of the fans is great and the materials used are strong and built to last. The colour scheme may not appeal to everybody but anybody seeing the brown and beige instantly knows the brand and I can see why Noctua do it; that said, I would love to see these fans released in alternative colours as an option.

Clearly a lot of effort has gone into designing and developing the NF-S12As. They perform well, have a superb build quality and great acoustics.  Noctua really have done a great job on these fans and I am pleased to award them the Play3r editors choice award. Great job Noctua!


  • Performance
  • Design
  • Value

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