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.
Measurement of static pressure…
Finally, it is time to move further down the tunnel a bit. Just behind the fan is a static pressure sensing probe. Its position has been chosen with maximum measurement efficiency in mind. In other words, the sensors are placed at the points of highest pressure (although this is virtually the same everywhere in the unconstrained part of the tunnel).
The Fieldpiece ASP2, which is connected to the Fieldpiece SDMN5 manometer, is used to measure the static pressure in the tunnel. The latter also allows measurements in millimetres of water column, but we measure in millibars. This is a more finely resolved base unit for this meter. And only from there we convert the measured values into mm H2O to allow easy comparison with what the manufacturers state.
While we wrote when measuring noise levels that our results could not be compared with the parameters, that is no longer the case here. As long as the fan manufacturers do not embellish the parameters, they should quote approximately the same pressure values as our tests show. The most significant deviations can only arise at the level of varying accuracy of the measuring instruments, but these are negligible percentages.
The greater the difference between the manufacturer’s claimed values and ours, the less the specifications correspond to reality. If the claimed values are significantly higher, it is certainly an intention to artificially give an advantage to the fans on the market. However, if the manufacturer quotes a lower pressure value than we do, it points to something else. Namely, a weaker tightness of the measuring environment. The less tight the tunnel is, the lower the pressure you naturally measure. This is one of the things we tuned for an extremely long time, but in the end we ironed out all the weak spots. Whether it’s the passage for the probe itself, the flanges around the anemometer, even the anemometer frame itself, which is made up of two parts, needed to be sealed in the middle. Finally, the flap at the tunnel outlet must also be perfectly tight. That’s because static pressure has to be measured in zero airflow.
But there is one thing that often lowers the pressure of the fans a bit. And that’s protruding anti-vibration pads in the corners or otherwise protruding corners. In other words, when the fan doesn’t fit perfectly to the mounting frame at the inlet, and there are small gaps around the perimeter, that also affects what you measure. But we have not gone into this because it is already a quality feature of the fan. In the same way, it will “stand out” and perform a bit weaker than it has the potential to do with better workmanship, even after application by the end user.
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.