BeQuiet! Silent Wings 4 (BL117) in detail
The Silent Wings (Pro) 4 represent the pinnacle of computer fan range. The non-Pro variants stand out especially in system positions and are not well suited for radiators. This is by design and in line with the sort of “micro-segmentation” of BeQuiet. In a white design, like the one tested, it will be quite difficult to find other 140 mm fans that are quieter at comparable airflow.
Evaluation
If the 140mm Silent Wings 4 is installed in the “right” place, it can be a fan with extremely high cooling efficiency while still offering favorable price-to-performance ratio. High airflow per unit of noise is achieved primarily in system positions where the fan provides air circulation in the computer case. What predisposes it for excellent results in such conditions is both the efficient impeller geometry and the anti-vibration corners. These dampen the vibrations that the fan generates with a certain intensity, but by being softly mounted they become negligible and are unlikely to be behind secondary noise (of the case or other components that may be affected by the fan operation).
Vibration is very low even at maximum speed. These features would not be as attractive if the fan was not based on an attractive impeller design. Without external influences of obstacles (but also with them, for example on a filter or on a grille) the airflow of the Silent Wings Pro (BL117) in normalised modes according to the “same” noise level is often similar to that of the more expensive Silent Wings Pro 4 (BL099). This is because of the identical geometry of both the impeller and the fan tunnel. In application scenarios where the performance characteristics are not affected by the shape of the corners, the results of these fans are usually very close to each other. The Silent Wings 4 in the BL117 variant finishes a bit below the Silent Wings Pro 4 (BL099) mainly due to some difference in the materials that the two fans are made of.
The white impeller of the BL117 has a slightly different chemical composition than the black rotor (of the BL099), hence the different stiffness and thermal expansion of the materials used. As a result, different resonant frequencies are achieved and the tested Silent Wings 4 tends to be a hair noisier in the critical sound band. We captured similar behavior in thematic comparisons of the white and black Corsair AF120 Elite fans.However, these are not fundamental differences and it is possible that subjectively, you may not even be able to distinguish between them. It is mainly a matter of interest, namely to know why the compared results are slightly different.
The SW4 BL117 lags most behind the SWP4 BL099 at very low speeds where the BL117 starts to get noisier, which is cross-verified by the lower operating speeds in the quietest test mode (around 570 rpm). This is probably caused by mechanical things around the motor (it is also different to the SWP4), as confirmed by some vibrations at very low speeds below 750 rpm. While you can completely ignore these in terms of operation (and user perception), they do occur at the lower end of measurability and do a good job of explaining the various dependencies between fan characteristics.
The sound of the Silent Wings 4 (BL117) can be evaluated as rumblier due to the noisier low-frequency sound, this is also the case compared to the black SWP4 BL099. But again, the differences are quite small.
The bigger and already significant differences with the SW4 (in general, regardless of the specific variant) compared to the SWP4 are in the cooling of the liquid cooler radiators.Because of the leaky corners, the airflow drops by up to 25%. In a situation like this, it makes sense to pay extra for the SWP4 just because they already have the tight “radiator” corners. However, they don’t matter as much when mounted on a tower cooler, just like they don’t matter in cases. In these scenarios, the tunnel around the impeller is a sufficient seal. And that brings us to the biggest advantage of the SW4 (compared to the SWP4). This fan is cheaper and thus has a significantly better price/performance ratio. That is, unless in your case the corners reduce the airflow through an obstacle.
Since Silent Wings 4 is mainly profiled as a system fan, it is important to point out one more important thing about it. And that is the possible collision of an unreinforced nylon filter with the impeller. In such cases, the latter can rub against the mesh, resulting in a very unpleasant sound. Here, care must be taken either to keep the fan away from the filters (as BeQuiet! does in its cases) or to have the mesh reinforced in some way – typically a frame that extends well in front of the fan impeller. These are, of course, compromise solutions that may increase noise to some extent, but avoid incompatibility. And then, of course, there are the various fan offset inserts, but these in turn increase the overall thickness.
Among white 140-millimeter fans, the BeQuiet! Silent Wings 4 (BL117) is one of the “best” options. Of course, the condition is installation in an optimal environment.
English translation and edit by Jozef Dudáš
| BeQuiet! Silent Wings 4 (BL117) |
| + Suitable for every use case |
| + Cooling efficiency (airflow/pressure per unit of noise) at a very high level... |
| + ... decisively beats even the most efficient 120 mm fans |
| + Very high efficiency even with plastic dust filters |
| + Wide speed range plus passive operation |
| + Extra low, negligible vibration |
| + Exceptionally powerful motor (almost 5 W) |
| + Interchangeable mounting corners. Two types depending on the specific application... |
| + ... and finally with an elegant (de)mounting system |
| + Assumption of a very long service life |
| + Decent build quality |
| - Slightly rumblier sound, which might be unpleasant for some people |
| - Possible collision with a nylon dust filter |
| Approximate retail price: 23 EUR |
- Contents
- BeQuiet! Silent Wings 4 (BL117) in detail
- Overview of manufacturer specifications
- Basis of the methodology, the wind tunnel
- Mounting and vibration measurement
- Initial warm-up and speed recording
- Base 6 equal noise levels…
- ... and sound color (frequency characteristic)
- Measurement of static pressure…
- … and of airflow
- Everything changes with obstacles
- How we measure power draw and motor power
- Measuring the intensity (and power draw) of lighting
- Results: Speed
- Results: Airlow w/o obstacles
- Results: Airflow through a nylon filter
- Results: Airflow through a plastic filter
- Results: Airflow through a hexagonal grille
- Results: Airflow through a thinner radiator
- Results: Airflow through a thicker radiator
- Results: Static pressure w/o obstacles
- Results: Static pressure through a nylon filter
- Results: Static pressure through a plastic filter
- Results: Static pressure through a hexagonal grille
- Results: Static pressure through a thinner radiator
- Results: Static pressure through a thicker radiator
- Results: Static pressure, efficiency depending on orientation
- Reality vs. specifications
- Results: Frequency response of sound w/o obstacles
- Results: Frequency response of sound with a dust filter
- Results: Frequency response of sound with a hexagonal grille
- Results: Frequency response of sound with a radiator
- Results: Vibration, in total (3D vector length)
- Results: Vibration, X-axis
- Results: Vibration, Y-axis
- Results: Vibration, Z-axis
- Results: Power draw (and motor power)
- Results: Cooling performance per watt, airflow
- Results: Cooling performance per watt, static pressure
- Airflow per euro
- Static pressure per euro
- Results: Lighting – LED luminance and power draw
- Results: LED to motor power draw ratio
- Evaluation
Is the very low speed characteristics similar to that observed in CPS RZ120?
This fan would have been much more competitive if it were to have closed corners by default. The corner swapping gimmick doesn’t seem to offer any actual benefit to me, as the vibrations are already low and similar results in dampening could already be achieved by using rubber mounts. They definitely could have saved some cost and/or priced the fan even more competitively by using integrated, closed corners instead of this gimmicky design.
That said, for users willing to DIY, this should still be a great radiator fan. All you need is some tape to seal up the corners, saving you quite a bit of money.
I mean the F5 R120. Confused with the cooler names.
Yes, if you encounter a lower airflow at the same noise level, a similar characteristic (as with the Silent Wings 4 BL117) is also found in the F5 R120. More fans have this. At such low speeds, the non-aerodynamic sounds must be extremely quiet to leave room to set the speed high enough for leading rankings.
Replacing the corners of the BL117 is really useful if only just to be able to install this fan on a radiator of a liquid cooler, where the SW4 doesn’t make much sense. Although the SW4 doesn’t need to be smeared too much in this scenario. Sure, due to the significant drop in placement compared to other fans, the urge is there, but at higher speeds it even outperforms the NF-A14. Sure, for a fan with modern geometry it’s more of a failure, but…
Using tape to seal the corners is a good DIY “trick”. 🙂
How would you compare it to the Pure Wings 3? This fan seems to constantly get outperformed by its cheaper sibling. The Pure Wings 3 does have a lower RPM limit, but there doesn’t seem to be other major disadvantages by going for the Pure Wings instead.
Now I’m really curious how the high speed, 9-blade version of the Pure Wings 3 performs.
The 140 mm Pure Wings 3 with 7 blades often seems to be a balanced (and a hair more more efficient) solution like the Silent Wings 4 (BL117). Although we have the SW4 in the white variant, which probably tends to be a bit noisier. These small differences (in tonal peaks) do not show up on radiators, where the tested PW3 variant has a significant advantage for obvious reasons (good sealing corners). We are also curious about the 9-blade Pure Wings 3 in 140 mm format. We will probably get to it after the announced Arctic P14 triple fan test (PWM PST, PWM PST CO and Max). 🙂
The Pure Wings 3 has a MTBF of 60 000 hours, which can be a disadvantage compared to Silent Wings 4 (with 300 000 hours). Lower robustness of critical parts in terms of durability (or change of properties over time) can also be indicated by the smaller impeller hub (of the PW3 BL108) and also at higher speeds relatively higher vibrations (again of the PW3 BL108), which could also indicate higher manufacturing tolerances. Of course, these vibrations could also be due to vibrations on the blades, but I assume they will be composed of several sources. And one of them will be related to the quality level of the impeller centering.
I guess the P14 trilogy will be consecutive releases then.
It’s a shame that we can’t have a Silent Wings 4 that comes with sealed corners, otherwise we’d have a reliable (and strong performing) 14 cm fan in the ~20$/£ price range that would compete very favourably vs. the Noctua A14 for example. I guess that’s done to prevent cannibalising their sales of their own flagship, but I’m not sure if it’s a smart move given the tough competition…
Yes, the next test will be the P14 PWM PST CO and I will conclude the trilogy (on Monday?) with the Max model.