Static pressure measurement…
With the Mobius 120 OC fan, Cooler Master could prove that it has worked on and avoided the rookie mistakes of older models. Partly yes, it removed some flaws, but it added (or strengthened) others in the process. Still, the current most expensive 120 mm CM fan has one ace up its sleeve, for which it will be extremely attractive in some use cases. Again, though, this is… how to put it… a somewhat “peculiar” execution.
Static pressure measurement…
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.
- Contents
- Cooler Master Mobius 120 OC 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)
- Static pressure measurement…
- … and 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 by 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 grill
- 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
I found your website in the course of my accidental search, the evaluation is detailed and respectful, I have a certain demand for RGB now, and Cooler Master said that the performance of mobius 140 ARGB is very powerful, there are too few evaluations now, I hope you can give it a look Make a review, many thanks.
We will gradually test all available fans. Only those that will stop selling over time will be unlucky (or lucky, depending on your point of view…).
We are excited to have a new reader. We welcome you dearly. 🙂
For the price, there are unfortunately too many flaws. The only application where the fan is strong is running at full speed disregarding noise, and even at that niche, the 12 cm Silent Wings Pro 4 is very close (and I would expect extremely tough competition from Phanteks T30 and Lian Li P28 as well). The poor PWM implementation on a modern fan is also very puzzling to me, especially at that price point.
The fan could be interesting server-grade solution. Maybe next time, I mean with ultra-long-life bearings and without vibrations.
I also tested Mobius 120 OC on thinner radiator recently, I can say this fan is one of the worst choice at its price.
There are many products on the market that obviously surpass Mobius 120 OC.
In terms of maximum airflow and price, Sanyo Denki 9G1212P4H06-4P, Thermalright TL-B12 EXTREM, Arctic P12 Max can perfectly replace Mobius 120 OC.
In terms of noise-airflow efficiency, PH-F120T30, NF-A12X25 and SW Pro 4 definitely outperform it.
Unlike Mobius 120(P), Mobius 120 OC seems difficult to survive the competition.
Thanks for the cross-verification of the results. 🙂
Actually I doubted my result of Mobius 120 OC because it showed 20%p lower noise-airflow efficiency than PH-F120T30, which was unbelievably poor result for an expensive fan. Now the cross-validation is possible with your thinner radiator test, and the two results are showing similar tendency about the fan. Thanks a lot!
I would LOVE to see you review the regular (non OC) Mobius fans. Particularly the 120p RGB version. It would be interesting to see just how close or far away from the OC performance they are.
Thanks for the tip. As long as the Mobius 120P RGB doesn’t stop selling before we can get our hands on it, we’ll be sure to include it in our tests. Gradually all fans available in the shops will be put in a confrontation. 😉