Everything changes with obstacles
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.
Everything changes with obstacles
So far, we have described how static pressure and airflow measurements are made under conditions where the fan has no obstacles in its path. In practice, however, fans do not usually blow into an empty space, but have a filter, grille or radiator in front of or behind them, the fins of which need to be pushed through as efficiently as possible.
We will also measure both airflow and pressure through practical obstacles for the reasons stated above. These include two types of filters that are usually used in PC cases. One fine – nylon and the other plastic with a thinner mesh. One other obstacle is the hexagonal grille perforated at 50%, on which the vast majority of fans – intake and exhaust – are installed. In some cases, we measure the effect of the obstacles on the results at positions (behind or in front of the rotor) that are used in practice. All obstacles are both pushed through to detect pressure drops, but also pulled through, which in turn speaks to the impact on airflow.
We use two radiators that differ in thickness and fin density. The EK CoolStream SE120/140 is 28 mm thick and the FPI is 22, the Alphacool NexXxoS XT45 v2 is thicker (45 mm) but with less FPI. CoolStream’s fin disposition is also similar in parameters to AIOs. The results on the NexXxoS will again be attractive for those who build their own water cooling loops, where the fans should work well even at low speeds – hence the lower fin density.
These obstacles and especially the radiators, but also the grilles, increase the mechanical resistance in front of the fan, resulting in higher noise levels. However, we will still tune the fan speeds to the specified noise levels of 31 to 45 dBA. Naturally, the speeds will always be lower than when testing without obstructions, but we will maintain the noise levels for clarity. The different noise levels with and without obstacles will only be at maximum power. In this mode it will also be nice to see how the fan design works with the obstacle and in which case the noise level increases more and in which less.
- 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. 😉