Silent Wings is the top-of-the-line series from be quiet! Now, the manufacturer has released the new generation of this famous series named Silent Wings 4. As usual, there are multiple types of fans available in 120mm and 140mm sizes. The most premium is Silent Wings PRO for 120mm and 140mm.

be quiet! has sent us their new fans for testing including Silent Wings 4 140mm PWM High-Speed. These fans are here for one particular test. More on that later in the content. be quiet! has come up with new design elements and in that, they have strived to bring a balance between their traditional outlook of the fans and performance improvement. The result is impressive-looking and high-performance Silent Wings PRO.

In this content we are taking a look at Silent Wings 4 140mm PWM High-Speed. Some of their salient features are:

  • Optimized fan blades for the highest performance on radiators and heat sinks
  • Small tip clearance and a fan frame with funnel-shaped air outlets for extremely high air pressure
  • The very silent operation even at maximum speed
  • 6-pole fan motor and fluid-dynamic bearing for less vibration and very smooth operations
  • Anti-vibration mounting with push pins and screwed installation option
  • The super-long lifespan of up to 300,000h
  • Elegant look with high-grade fan sticker in an all-black design
  • 5-year manufacturer warranty

Product:               be quiet! Silent Wings 4 140mm PWM High-Speed

Pricing:                 SCAN UK Pricing £23.99 [At the time of review]

                                MSRP is €24.90



be quiet! Silent Wings 4 140mm PWM High-Speed Fans Specifications

Specifications 1

be quiet! Silent Wings 4 140mm PWM High-Speed Fans Dimension

Dimension 1

Packaging and Unboxing

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The fan is shipped inside a paperboard packing box in the typical black color theme from be quiet!. The tagline is “No compromise Silence and Performance”.

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The salient specifications are listed over here. The fan is listed for up to 78.4 CFM airflow and 2.36mmH₂O air pressure at the 1900 RPM mark.

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There are two more boxes inside the main packing box. The top box is labeled as Accessories and it contains the screws and mounting corners. The fan is in the bottom container.

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The above picture shows the fan in its box.

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A user guide is provided in the box.

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The above picture shows the screws and the push pins provided in the accessories box.

be quiet! Silent Wings 4 140mm PWM High-Speed Fans Closer Look

Let’s take a look at the fans.

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The Silent Wings 4 are available in 120mm and 140mm sizes in different configurations. We are taking a look at the Silent Wings 4 140mm PWM High-Speed. The user of PWM indicates that DC-based versions are also available. These are all black color fans which are non-RGB. The main focus here is the ultimate performance that a fan can deliver. be quiet! has come up with a new blade design and they have reduced the clearance for the tip of the blades meaning that the gap between the frame and blades is reduced. The tip clearance plays a key role when it comes to sustaining the high pressure while delivering the flow as it reduces the turbulence. The fan has 7 blades with a textured surface in an altered layout. The center of the fan has a large diameter. The branded fan sticker is also in black color. The main frame is circular with detachable mounting corners. Compared to Silent Wings 3, there is another key difference. We have a circular frame on the Silent Wings 4 which was not the case on the predecessor. Also, the funnel shape design was implemented on the inlet of Silent Wings 3 which is now on the outlet of Silent Wings 4.

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The above picture shows the close-up of the mounting corner. These fans have detachable mounting corners and be quiet! has provided one more set in the accessories bag which can be put on conveniently subject to the requirement. The pre-installed corners can be used in tandem with the push pins and allow the user to install these fans in the PC case for ventilation with less noise output occurring from the vibration. You would need to change the corners if installing these fans over the radiator.

We almost have a square shape design of these fans though I personally prefer the complete square outlook provided on the PRO versions of the Silent Wings 4.

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The above picture shows the other set of mounting corners:

  • Radiator corners
  • Anti-vibration corners for the case [Pre-Installed]

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The above picture shows both types of corners. The toppers are for the PC Case whereas the ones on the bottom are for the radiator. They have anti-vibration pads on both ends. The central portion is also removable.

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The above picture shows the fan with all corners removed. There are two plastic clips on each corner that hold the attached corner.

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The above picture shows the inner side of the radiator corners. They all have the number 3 mentioned there.

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The pre-installed corners have a number 2 mentioned on the inner side.

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The above picture shows the fan with radiator corners installed.

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The above picture shows the frame of the fan. The fan’s frame is sturdy. There is a be quiet! branding over the sides.

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We can spot two carved arrow indicators on the frame. These are there to identify the direction of airflow and the direction in which the blades will spin.

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The backside of the fan shows a four-arms assembly with one arm widened to provide passage for the wires. The manufacturing date is also mentioned. The fans are made in China. Each fan draws 0.40A. These fans don’t have a slider button on the backside to control the speed of the fans. This option is only available in the PRO series.

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Looking at the arms, we can see that they are designed in an angular manner to facilitate air outflow. This goes to show the length be quiet! has gone to provide good performances from these fans.

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Each fan has a 4-pin PWM connector using a well-sleeved cable.

be quiet! is using Fluid Dynamic Bearing in these fans having a life span of 300,000 hours. These bearings reduce the vibration which helps in reducing the overall noise output. On top of that, these fans are using 6-pole, 3-phase motor.

The salient specifications of the fans are:

Dimension 140x140x25mm
Fan Speed at 100% PWM 1900 RPM
Noise Level at 100% PWM 29.3 dB(A)
Airflow at 100% PWM 78.4 CFM
Air Pressure at 100% PWM 2.36 mmH₂O
Voltage Range 5~13.2VDC
Input Power 4.8W
Input Current 0.4A


The following test configuration is used: –

  • Intel i7 12700k
  • XPG LANCER RGB 32GB @ 6000MHz DDR5
  • GIGABYTE GeForce RTX 3060 VISION OC Rev.2
  • Sabrent Rocket 4 Plus 2TB NVMe SSD
  • bequiet! Straight Power 11 1000W Platinum PSU
  • Praxis Wetbench
Clock (MHz) 5100 P-Cores, 4000 E-Cores
Voltage (V) 1.250
Turbo Boost Disabled
C-States Disabled
Speed Step Disabled
Thermal Paste Alphacool Subzero
Thermal Paste Application Dot Method in the center.
Test Run Time 30 minutes
Idling Time 10 minutes
Fan Speed 50% and 100% PWM Duty Cycle
Pump Speed Full speed through Molex connector
Software CINEBENCH R23 Multi and HWInfo64
O.S Microsoft Windows 11 22H2


We have used Alphacool Subzero thermal paste for testing. 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. The fans were connected to the NZXT FAN Controller and were set to run at full speed and 50% PWM duty cycle. The pump was running at full speed as well. Cinebench R23 is sued to stress test the CPU and HWInfo64 are used to monitor the sensors.

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The fun part is that these fans were put on the gigantic radiator from Alphacool. It is a NexXxos XT45 Full Copper radiator in 1260mm size. The above picture shows these fans installed on the fan grill.

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The above picture shows these fans installed on the radiator.

Test Loop Configuration and setup

We wanted to set up a modular loop that would require minimum handling and easy swapping of components including the radiators since multiple-size fans are to be tested. This was achieved using Quick Disconnect fittings in the following configuration:

  • Quick Disconnection between the CPU Water Block and the Pump/Reservoir Combo
  • Quick Disconnection between the CPU Water Block and the Radiator
  • Quick Disconnection between the Radiator and the Pump/Radiator Combo

CPU Water Block

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We have used the premium water block from Alphacool which is Eisblock XPX AURORA PRO Digital RGB – Full Brass. You can check it out in the dedicated content by clicking here.


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We have used the Alphacool EISBECHER D5 AURORA ACETAL/GLASS 250ml reservoir with VPP APEX pump.

Other Components

We have used Alphacool black TPV tubes and 16/10mm compression fittings along with quick disconnect fittings. Additionally, the Alphacool Eiszpfen Temperature Sensor G1/4 IG/IG to AG adapter is used which is a 10KOhm sensor to record the temperature of the coolant. The 2-pin connector was attached to the 2-pin sensor on the motherboard.

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The above pictures show the unit ready for testing.


be quiet Silent Wings 4 140mm PWM High Speed Thermal Performance 12700k

This is one heck of a good performance from the new fans from be quiet! as they have surpassed the famous NF-A14 and even NF-A20 PWM fans from the Noctua. Even at 50% PWM cycle these fans were delivering the performance level of NF-A20 fans running at their full speed.


The ambient noise level is between 31-32 dBA. The 9x be quiet! Silent Wings 4 140mm PWM High-Speed fans were making roughly 49 dBA at full speed and roughly 37 dBA at 50% duty cycle. This is quite impressive as there is only 1 dBA difference between these fans and that of Noctua NF-A14.

be quiet! Silent Wings 4 140mm PWM High-Speed Fans Conclusion

We have tested the new fans from be quiet! namely Silent Wings 4 140mm PWM High-Speed. Silent Wings is top of a line cooling fan from the manufacturer and they have released a new generation of fans called Silent Wings 4. There is an elite version called PRO available in 120mm and 140mm which we will be taking a look at in the next content. Then there are 120mm and 140mm versions in non-PRO in different configurations.

be quiet! has sent us 9 fans in 140mm size (Silent Wings 4 140mm PWM High-Speed) for special testing. Recently, Alphacool sent us the monster radiator called NexXxos XT45 Full Copper 1260mm SuperNova. This gigantic radiator has a surface area of 200x200x45mm and can house either 9x 140mm fans or 4x200mm fans and a combination thereof. These fans are particularly sent for this testing.

The new features include an altered blade layout with a narrow gap between the fin tip and the frame which would result in higher air pressure on the edges. Another salient feature is the removable corner mount. These fans come with plastic and rubber corner mounts, each serving a specific purpose mainly vibrational noise. The pre-installed corners are suited for ventilation tasks for which be quiet! has provided push pins. The other set is used to install these fans on the radiator.

These fans are using Fluid Dynamic Bearings having a life span of 300,000 hours and a 6-pole, 3-phase motor which in conjunction, produce less vibration and are heat efficient as well. The SST-SF120 fans also employ the same bearing and same motor. These fans are rated for up to 1900 RPM. The operating voltage range is 5~13.2VDC. This fan draws 4.8W using 0.4A at 12VDC. The airflow rating is 78.3 CFM with a static pressure rating of 2.36mmH₂O at 12VDC. We expect these fans to perform well given these high-end specs.

The be quiet! Silent Wings Pro 140mm PWM High-Speed fans have an MSRP of Euro 24.90. They are listed at SCAN UK Pricing £23.99. be quiet! is offering 5 years warranty on these fans. The thermal performance of these fans on the radiator is excellent as per our testing. They also have a better noise-to-performance ratio. Our charts are indicative of this superb performance as these fans are sitting on top of the Noctua NF-A14 and NF-A20 PWM fans. The Silent Wings 4 140mm High-Speed fans with their classic look, superb build quality, and solid performance punch, have won our Performance Award.

Thanks to be quiet! for the provision of the fans.

Enos Tech Performance Award