Noctua NF-S12B FLX Review

For high-end PC’s, cooling always played an important factor in the system’s stability. Of course, there has to be a balance between the cooling efficiency and the noise levels produced. Today we will be taking a look at the Noctua NF-S12B FLX, a 120mm high-quality chassis fan.


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Noctua was founded in 2005 and their headquarters are located in Austria. They specialize in silent PC cooling products.

Following the popular NF-S12, the Noctua NF-S12B FLX is a next generation silent cooling fan, featuring Noctua’s advanced SCD2 technology that helps the fan run  quiet and smooth with constant torque. Furthermore, its advanced blade geometry increases airflow efficiency up to 10% compared to previous models. With the advanced SSO Bearing and adjustable RPM settings, the Noctua NF-S12B FLX is a premium fan designed to give the system that extra boost in cooling, with the user being the one who decides the balance between cooling efficiency and noise levels.

Let’s take a look at NF-S12B FLX’s detailed specs, taken directly from Noctua’s website:

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From the features, we clearly understand that for a fan the technology is quite sophisticated.


 A Closer Look – Package

The Noctua NF-S12B FLX comes in a flashy luxurious box. In the front of the package we find the Noctua fan with a clear plastic semi-window, with the fan’s main features illustrated at the right side.

Here is the back of the box with all the unique features of NF-S12B FLX  listed.

In the additional panel of the back of the box  we see some diagrams and graphs showing us the sophisticated motors, bearings and blades of NF-S12B FLX.

The packaging includes the NF-S12B FLX 120mm Fan, 4 vibration compensators, 4 standard fan screws, one 3-pin to 4-pin adapter, and 2 fan speed adapters.

These are the four vibration compensators  which can be used instead of mounting the fan with screws. They help keep the fan to run steadily as they absorb vibrations during operation.

Here are the 3 to 4 pin power adapter and the  4 installation screws. The adaptor enables connectivity directly to the PSU in case the connection with the motherboard is not possible. As for the screws, we strongly recommend to mount the fan with the vibration compensators instead.

To prevent noise Noctua provides two fan speed adapters. The L.N.A. which drops the RPM to 900 and U.L.N.A., which drops the RPM to 600. The airflow slows down with the use of those adapters, but the noise levels are also greatly decreased.


A Closer Look – The Fan

In the center we see the Noctua’s logo. The fan cable is covered by a nice sleeve and is long enough for even the biggest full tower cases, so there will be no problems installing the fan. Furthermore, the model follows the same colour combinations as all Noctua products.

The unique feature of this fan are the eye-catching fan blades. They allow better airflow within the case due to the wider gaps between the fins.


Test Setup and Procedures

The machine on which we tested the fan is:

Processor: Intel Core i7 920
CPU Cooler: Noctua NH-C12P
Motherboard: Asus P6X85D Premium
RAM: Mushkin Redline 6GB-998691
VGA: Gigabyte GTX480 1536MB
HDD: Velocity Raptor 150GB
PSU: Nexus 1000W
Case: Thermaltake Armor VA8003BWS
Operating System: Windows 7 64-bit

We tested the NF-S12B FLX against two fans of the same category:



The tests we took included the following:


  • Motherboard Temperature in Idle Mode, fan installed on chassis
  • Motherboard Temperature in System Load Mode, fan installed on chassis
  • CPU Temperature in Idle Mode, fan on CPU heatsink
  • CPU Temperature in System Load Mode, fan on CPU heatsink
  • Noise Levels


Testing Results- Motherboard Temperatures2mother idle temp - Noctua NF-S12B FLX Review
3mother load temp - Noctua NF-S12B FLX Review

In our motherboard tests, the Noctua NF-S12B FLX was a clear winner, achieving the lowest temperatures in both Idle and Load system conditions.


Testing Results – CPU Temperatures and Noise Levels

4cpu idle temp - Noctua NF-S12B FLX Review5cpu load temp - Noctua NF-S12B FLX Review

4 cpu  idle temp - Noctua NF-S12B FLX Review

Noctua’s fan also proved to be the best among the 3 contesters, considering CPU temperature when installed on a CPU heatsink. In idle mode there was a 3 degree celsius diffrence from Phobyas Nano and 2 from Scythe’s Kama Flow. In system load, Noctua’s fan achieved a whole 5 degree difference from the las Phobya Nano-G12.

6noise levels - Noctua NF-S12B FLX Review

But apart from the impressive performance, what about noise? We were excited to see that the Noctua NF-S12B FLX performs well, while keeping the noise levels low. There is a 7Db drop from Phobya Nano and an impressive 13Db difference from Scythe’s Kama Flow 2. Practically the fan was pretty silent for the extra cooling performance it provides, as we didn’t notice any noticeable noise coming out of the chassis during its operation.

Overall, the results were pretty impressive. The Noctua NF-S12B FLX delivers great air pressure performance and the noise levels are also kept very low.



This is one of the best fans we have ever tried. It offers excellent air flow but the real advantage is that it is extremely quiet.
Overall construction is clean and the sleeve for the cable is very nice. As we see the package includes all the good stuff like sound dampeners and adapters for lower speed.
The fan is a great addition to anyone’s case setup or to use along with a CPU heatsink.

The Noctua NF-S12B FLX is sold across Europe for 20 euros, which is a little bit expesive for a 120mm fan, but based on the results you get what you pay for, as the fan is totally worth its money, combined withe the fact that you get an impressive 6-year warranty.


(+) Extremely Quiet
(+) Solid Design
(+) Excellent air flow
(+) Exceptional 6 years warranty


(-) Price (but you get what you pay for)


Thus, we give the Noctua NF-S12B FLX a rating of 9.5/10 and our Editor’s Choice Award.


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