be quiet! Silent Wings Pro 4

[testman78]

Introduction

be quiet! has been working away on its next-generation Silent Wings 4 fans for a couple of years now, with the first 3D-printed prototype arriving in 2020. Now in 2022, the new Silent Wings 4 fans are on shelves. The Silent Wings Pro 4 fans are primarily designed to offer great airflow for heatsinks and radiators, but they also work great as case fans. The fans feature a three-phase, six-pole motor for increased efficiency and reduced vibration, fluid-dynamic bearings for a 300,000-hour lifespan, and a new blade arrangement. The Silent Wings Pro 4 fans have been designed with significantly faster speeds in mind (which is entirely true!). This has, of course, resulted in slightly higher levels of acoustic output, but this is, of course, pretty much entirely relevant to the actual operating speed of the fan. The Pro models can offer different maximum speeds thanks to a new slide switch. With the Silent Wings Pro 4 120mm PWM up to 3,000 rpm are possible, with the Silent Wings Pro 4 140mm PWM up to 2,400 rpm.



In the table below you can see all Silent Wings Pro 4 series fans. As you can see special emphasis was placed on improving the static air pressure in the new edition. This is especially important if you want to install the fans on CPU heatsinks and water cooling radiators.




Packaging & Contents

When you hold the packaging in your hands, you immediately notice that you are dealing with a higher-priced premium product, thanks in particular to the elegant design. The packaging for 120/140mm models is, in terms of presentation, pretty much identical. At the front you can see an image of the fan including the most important technical data, further to the left runs a silver stripe with the black lettering "High-End", which makes it clear what the buyer is holding in their hands.



On the back of the packaging we find its specifications table, as well as a description of the product in several languages ​​and a QR code that will take us to the product page.



When it comes time to peek inside the box, lift the flap over the box's top to expose what is inside of it. With this level of attention to detail, not only is the Silent Wings Pro 4 in perfect condition, it raises our hopes as to what to expect from the product if the box is this high-end! We can also see things are nicely packaged with the fans and accessories being separated.



Alongside the fan, users will also find some rubber noise dampeners, screws and rubber and hard plastic mounts. It’s fair to say be quiet! have tried to make their Silent Wings Pro 4 fans as versatile as possible.





We can find also the usual instruction manuals and information pamphlet.





A Closer Look

The fans have a black frame and black, distinctively ribbed fan blades. When you first get the fans out of the box, they won’t have their mounts on them. They are easy enough to put on though and we will look at that shortly. The fan blades have a unique ripple like design to them to help them provide better air flow while remaining as quiet as possible. On each side, a rubber ring surrounds the seven blades. They make it possible to limit the transfer of vibrations.



Its architecture also benefits from a reduced space between the frame and the blades and a funnel-shaped air outlet.



Compared to the Silent Wings 3 series, the fan blades now have a different shape and also feature a smaller gap between the fan blade and the frame (1.0 mm instead of the previous 1.2 mm).



We can also just barely see in the pic below that the PWM cable is indeed braided and goes into the heat shrink which goes almost into the frame of the fan, meaning very little bare wires are showing.



The cables of the Pro models are sleeved to a higher standard. Your plug is higher and can therefore be gripped and plugged in or removed more easily. The cables are about 50 cm long for all fans.



The white and orange logo of the predecessors has been replaced by a very subtle black logo. We saw the image of the backside of the fan that the wires that do show still have a black covering so aren’t an eyesore and still manage to fit in perfectly with the aesthetic of the fan.



At the rear we have the 6-pole rotor in the center. The Silent Wings Pro 4 offers a motor equipped with 6 poles as well as a dynamic-fluid bearing system. It has a lifetime of more than 300,000 hours. We can see the official model name, DC output, amperage and the RPM of the fan. The rear of the fan has a slider switch to the centre. This allows the user to manually set the fan speed and comes with three settings. This three-stage switch limits the maximum speed. With the Silent Wings Pro 4 120mm PWM, the maximum speed can be reduced from 3,000 rpm to 2,500 or 1,600 rpm and with the Silent Wings Pro 4 140mm PWM from 2,400 rpm to 1,900 and 1,100 rpm.



The Pro models also come with another mounting option that is specifically designed for use on radiators. These mounting corners are particularly close to the fan to prevent air leaks and thus create the highest possible static pressure.



In the accessory pack is where you will find the included mounts. The mounts themselves simply slide onto the fan and come in both rubber or hard plastic depending on your needs and wants.



With the corners removed, here you can see the tabs that act as anchors.



Once the mounts are on, you should be able to put the fan in any space designed for a 120/140mm fan. Myself, I go with the rubber mounts to help reduce noise from vibration.



Below you can see how the fan looks with the radiator corners installed.




Test System & Methology

The 120mm fans has been tested using a 360mm CPU liquid cooler, the Alphacool Eisbaer 360 at max. RPM.
The 140mm fans has been tested using a 420mm CPU liquid cooler, the Arctic Liquid Freezer II 420mm at max. RPM.
Thermal performance of the fan was tested on this test bench:

Intel i7 6850k
Asus Rampage V Edition 10
Ballistix Elite 4x4GB @ 3000MHz
Alphacool Eisbaer 360
Samsung 840 EVO 250GB
Corsair AX 1200i



Testing was performed on the Microsoft Windows 10 x64 Professional edition build version 1709. Noctua NT-H1 thermal paste was used. The fans were tested at 50% and 100% of their speed. The pump of the CLC was put on 100% of the speed. Asus RealBench v1.44 was used to stress test the CPU. RealTemp was used to monitor the temperatures. First, the stress test was run on the stock clocks of 3.6GHz at 1.14V VCore. XMP was loaded all the times. Reported temps are delta ones which are calculated by subtracting the average of each core’s maximum temps from the ambient temp. The benefit of using delta temps is that it covers the variation in the temperatures under uncontrolled environment. Next, the Chip is overclocked to 4.3GHz at 1.350V VCore. XMP is loaded as well. Stress test is run again using the same methodology as described above and delta temps are noted. Each run was of 60 minutes. The Eiswind 12 fans operate on the 12V DC. They are 4-Pin PWM fans with the rated speed of the 55-1700 RPM with ±10%. The reason I am giving the brief rundown of the Eiswind 12 fans is that these are the stock fans of the Alphacool Eisbaer 360 and hold a reference point for the comparison. For noise level testing, we only connected a single 120mm fan to the Noctua NA-FC1 fan control unit to make the results relevant.


Performance

On stock clocks of 3.6GHz, the be quiet! Silent Wings Pro 4 120mm PWM fans were doing 21.7°C at 50% of their rated speed while Eiswinds 12 were doing 23.57°C. At 100% of the rated speed, the be quiet! Silent Wings Pro 4 120mm PWM were doing 20.6°C whereas the Eiswinds 12 were doing 22.9°C. The performance range is 1.7°C to 2.3°C. It is coming at much better acoustics also.



With overclocked chip at 4.3GHz, the be quiet! Silent Wings Pro 4 120mm PWM were doing 41.3°C at 50% of their speed. They were doing 39.1°C at 100% of the speed. The Eiswind 12 were doing 44.63°C at 50% of their speed and 43.63°C at 100% of their speed. The performance range is 3.2°C to 4.5°C. The gap is getting bigger and mind you this level of performance is coming at much better sound pressure.



In the next graphs we see that the Arctic fans on the Arctic Liquid Freezer II 420 AIO has been swapped out for three be quiet! Silent Wings Pro 4 PWM 140mm fans. The CPU temperature dropped by 1-2°C.




The be quiet! Silent Wings Pro 4 Pwm 120mm stayed relatively quiet across the RPM range, with little audible wind noise at higher speed. Well, be quiet! took their sweet time with this, and it looks like it was all worth it in the end. be quiet! has impressed me with their Silent Wings Pro 4 120/140 mm fans when it comes to watercooling. The Silent Wings Pro 4 is a fantastic fan for this purpose, and I am quite pleased to see a product that has had performance and noise as metrics for R&D over RGB lighting. It outperformed even Noctua’s own NF-A12x25 to provide more context and it is about as quiet as the Corsair HD120(which I used to recommend to those prioritizing noise while still maintaining decent performance). As it stands today, and pending the cost factor which we will get into on the next page, the be quiet! Silent Wings Pro 4 is my overall top recommendation for watercooling fans from a performance/noise basis.




Final Thoughts

If you have skipped the previous few pages, I strongly urge you to reconsider and go through them. At the very least, read the previous page to better understand and appreciate what be quiet! has managed to do. It took a long time, as has been mentioned more than once over the course of this review, to where many lost patience and went with competing solutions. In the time period from when these fans were first teased to now, the fan market underwent an RGB revolution, if you will, to where any fan sold at the 30 euros price point in 2018 is expected to have addressable RGB LEDs and be supported by a software driver and LED hubs to be able to customize lighting by more than ever before. Indeed, fans in this price range are a combination of a fan and an LED strip to where many would fit right into a Mary Shelley novel rather than inside a PC case. The Silent Wings Pro 4 has none of these LEDs. Visually, the Silent Wings Pro 4 have now been made even simpler and rely on an elegant black manufacturer logo on a black background. be quiet! has included a plethora of accessories with the Silent Wings Pro 4 fans. These include rubber noise dampeners, screws, rubber and hard plastic mounts. All the new technologies and materials that be quiet! put in to the Silent Wings Pro 4 do help improve the performance and durability. The fan’s construction is top-notch, the frame feels super solid without any flex. Because of the blade design and the 1.0 mm tip clearance, the fan becomes a impressive all-rounder, which is suitable for both case ventilation and heatsinks/radiators cooling. be quiet! introduces a different blade arrangement and uses a funnel-shaped air outlet to increase static pressure and airflow. The Pro models also come with another mounting option that is specifically designed for use on radiators. These mounting corners are particularly close to the fan to prevent air leaks and thus create the highest possible static pressure. Also reserved for the Pro model are a high-quality sleeved cable and an easy-to-grip motherboard connector. At the rear we have the 6-pole rotor in the center. The Silent Wings Pro 4 offers a motor equipped with 6 poles as well as a dynamic-fluid bearing system. It has a lifetime of more than 300,000 hours. The rear of the fan has a slider switch to the centre. This allows the user to manually set the fan speed and comes with three settings. This three-stage switch limits the maximum speed. With the Silent Wings Pro 4 120mm PWM, the maximum speed can be reduced from 3,000 rpm to 2,500 or 1,600 rpm and with the Silent Wings Pro 4 140mm PWM from 2,400 rpm to 1,900 and 1,100 rpm. Jumping right into it and there is no denying the performance the be quiet! Silent Wings Pro 4 range has to offer. Not only did they out-perform the fans I tested them against, they have a lot of other features that will allow them to perform better than your average fans. Our graphs are showing the good improvement in the thermal performance when tested on the Alphacool Eisbaer 360 CLC and Arctic Liquid Freezer II 420. Their airflow and speed ratings have been validated. be quiet! has been known for selling fans with not just excellent performance, but also with how quiet they are. The Silent Wings Pro 4 fans are no different. Even at full blast, the fans were relatively quiet.



The Silent Wings Pro 4 120mm PWM cost 31.90 euros and the Silent Wings Pro 4 140mm PWM cost 32.90 euros. Premium fans are never cheap. As it stands, the price is too steep for most to do a full system replacement if you have more than ~360 mm of radiator space (triple 120 mm, say). All models in the new 4 series come with a full 5-year warranty from the manufacturer. The Silent Wings Pro 4 is a throwback from a company that revels in it, and the end results speak for themselves: it is a fantastic fan and my top recommendation for PC watercooling enthusiasts looking for something that is tangibly better from a performance/noise basis. If it were not for that 30 euros price point, I would have probably come close to making it a universal recommendation to where some people might even consider these to replace current fans.