SilentiumPC Sigma Pro 140mm PWM – Test and Review

The Sigma Pro series features four different models with dimensions of 120 x 25 and 140 x 25 mm designed as extremely silent and affordable upgrade fans for cases, CPU coolers and cooling radiators part of liquid cooling loops. The series includes:

  1. Sigma Pro 120 – 3pin powered and regulated working at 1200 revolutions per minute providing airflow level of 65.45 m³/h with maximum noise level of 12.9 dBA.
  2. Sigma Pro 120PWM – 4pin PWM powered and regulated working at 500 – 1600 +/- 10% revolutions per minute providing airflow level of 79,05 m³/h with maximum noise level of 15 dBA.
  3. Sigma Pro 140 – 3pin powered and regulated working at 800 revolutions per minute providing airflow level of 77.01 m³/h with maximum noise level of 10.9 dBA.
  4. Sigma Pro 140PWM – 4pin PWM powered and regulated working at 500 – 1400 +/- 10% revolutions per minute providing airflow level of 133,62 m³/h with maximum noise level of 22 dBA

For this test and review I received the most powerful model in the series, which is SilentiumPC Sigma Pro 140mm PWM. The fan was provided to me in a classic carton box painted entirely in white and light blue featuring a see through cut on the front side of the box, through which you can see the shape of the propellers and part of the frame. Of course on the front side of the box, the product name and few of the main technical details are described.

On the other hand, the full technical specification written in several languages and some additional explanations regarding the structure and the features of the fan are placed on the back side of the carton package. The box looks pretty stylish and has one more interesting peculiarity, which is actually a typing mistake in the name on the front panel. Anyway the package is not the main focus of this review, so let’s put it aside and check the structure of the fan.


SilentiumPC Sigma Pro 140mm PWM STRUCTURE

The fan itself is equipped with an entirely painted in black matte, pretty solid octagon frame with dimensions of 140 x 140 x 25mm designed to be installed on a 120mm mounting holes.

The interesting thing regarding the frame is actually the additional 4 metal brackets, which should be attached to each corner of the frame via small screws and give the owners of the fan the option to install the fan on 140mm case fan slot or CPU cooler compatible with 140mm fans. Of course both the four brackets and the four metal screws are entirely in black.

Brackets installed Brackets and bolts


On the other hand, Sigma Pro 140mm PWM is equipped with 9 pretty wide, with but not very sharply angled blades forming the entirely in black matte propeller, which is designed to provide the best possible airflow / static pressure balance, while maintain the lowest possible noise level.

And of course, to fulfill its cooling duties the fan is equipped with a 4pin PWM powered and regulated HSB hydraulic bearing made to last up to 50000 hours and to implement the connection between the frame and the propeller of the fan. The motor itself is powered and regulated by an entirely sleeved in black mesh 400mm long cable and connector.



With the fan being reviewed I believe it is time to put it aside and check the additional accessories provided in the package:

The standard SilentiumPC Sigma Pro 140mm PWM package features:

  1. a set of 4 metal screws for installing the fan to a case fan slot
  2. a set of 4 metal screws for attaching the brackets to the frame
  3. a set of 4 entirely painted in black metal brackets to install the fan on 140mm case fan slot
  4. a set of 4 white rubber dampers to reduce any vibrations of the fan

I believe I’ve spent more than enough time checking the fan’s structure and accessories so I guess it is time to check how it will perform.


SilentiumPC Sigma Pro 140mm PWM TESTS

The tests will be conducted in my standard way. I will install the fan and test it at 5V/7V/9V/12V and my goal will be to check the performance of the product in real conditions. It will be tested under close-to-perfect conditions, not taking into account any external factors. The results achieved during the tests can in no way be the same if the models are mounted on a cooler or on the case fan slot of any modern computer case. I will measure the amount of air going through the fan for one hour and its speed. For this I use a fan controller, a voltage meter, an anemometer and a stand made specifically for this purpose.

And this is what the fan looks like installed on my test stand:

The test results are shown in the following charts:

Airflow through the fan at 5V, 7V, 9V, 12V

Propellers rpm during the tests at 5V, 7V, 9V, 12V.

The anemometer showed the following air speed passing through the propeller:

After mounting the fan onto the stand, and leaving it to rotate for about 30 minutes at maximum speed, it was time to do the tests.

As with my other tests, again I started with a gradual increase of the voltage through the Lamptron FCT starting at 0V and SilentiumPC Sigma Pro 140mm PWM made at least one full revolution at about 6.5V. To do the first test I had to decrease the operating voltage to 5V.

Test at 5V:

At the first test conducted at 5V, the fan was rotating at exactly 600 revolutions per minute and providing airflow level of 45.6 cubic metres per hour. At the first test, the fan was absolutely silent.

Test at 7V:

Through the second test conducted at 7V, Sigma Pro 140mm PWM was providing airflow level of 71.04 cubic metres per hour, while rotating at stable 900 revolutions per minute and maintain no noise at all.

Test at 9V:

The third test conducted at exactly 9V, showed significant performance boost and airflow level of 96 cubic metres per hour, while rotating at 1200 revolutions per minute. Through the third test the fan started generating a tiny noise coming out of the air passing through the blades of the propeller.

Test at 12V:

At the last test conducted at 12V sharp, Sigma Pro 140mm PWM reached its maximum performance, which was revolutions per minute count of 1500 and airflow level of 120.48 cubic metres per hour. Through the last test the generated noise was much more distinct.

With the review and the tests performed I believe it is time to express my feelings regarding the product.


SilentiumPC Sigma Pro 140mm PWM CONCLUSIONS

1. SilentiumPC Sigma Pro 140mm PWM Performance:

After I spent few hours dealing with Sigma Pro 140mm PWM’s package, structure and accessories I find this fan a really attractive and versatile product. The fan itself it is definitely made to offer a wide operational and performance range to suit every cooling need. It is capable to operate as a case fan installed on a 120mm or 140mm fan slot to provide nice and steady breeze inside every modern case while running at low operation voltage and at the same time to be a main cooling unit providing serious airflow and static pressure level to cool big CPU heat-sinks and water-cooling radiators while running at full speed..

In both cases this model will do the job and will keep the hardware for which is responsible cool, stable and most probably quiet. And since I mentioned the noise…

While the fan is working at 5V or 7V it is deadly silent, while with the voltage increase the fan starts generating a tiny noise, which at 12V is pretty distinct. Anyway this is absolutely acceptable since the fan is also delivering a very good and stable airflow level. And to achieve good cooling results, the noise should be sacrificed, which is totally expected.

2. SilentiumPC Sigma Pro 140mm PWM Appearance:

In matter of appearance, I should say that SilentiumPC Sigma Pro 140mm PWM is designed as a very simple to remain totally neutral installed in a case with black/grey colour scheme or mounted on a CPU cooler and water-cooling radiators.

I think that SilentiumPC Sigma Pro 140mm PWM deserves the following reward:


SilentiumPC Sigma Pro 140mm PWM has been added to the 140mm fans catalogue.

Official price (MSRP): SilentiumPC Sigma Pro 140mm PWM:  9 euro

Warranty: 24 months

I thank SilentiumPC for the provided test sample.


SilentiumPC Sigma Pro 140mm PWM – Test and Review
8.5 Total Score

Noise Level
Additional accessories
User Rating: 3.87 (3 votes)

Dobrin Krastev is the owner, reviewer and newsman of with more than 15 years' experience in personal computers, server and storage systems, UPS, peripheral devices and software. Passionate about testing and reviewing, AMD overclocking using AM3 990FXA and AMD FM2 A85X test systems and building modding projects.
  1. Reply SALVO 17.03.2017 at 14:23

    Hi… But this is a copy of the thermalright?

    • Reply Dobrin Krastev 17.03.2017 at 14:26

      Hello Salvo,

      Actually you might be right and this is normal.
      There are many examples of products, which are designed and manufactured by a company and later sold and labeled with another brand.

      I can’t confirm if this is the case, but they indeed look similar.

      Best Regards

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