Endorfy Stratus 140 PWM in detail
The cheapest 140mm fan we’ve tested so far beats even significantly more expensive 120mm models at comparable noise levels. That’s because of the use of a larger cross-sectional area, as well as the efficient impeller geometry that the Stratus 140 PWM definitely has. “Cheap” fan doesn’t necessarily mean “weak”, though of course there are some compromises based on more limited manufacturing resources than with more expensive fans.
Evaluation
First of all, it’s worth highlighting the extremely impressive price-to-cooling efficiency ratio, or airflow per unit of noise. The Stratus 140 PWM has taken the top spot in this regard, where it clearly dominates (for now…). The cheaper 140mm fans are generally well suited to achieve the top ranks here, as compared to the 120mm fans, they have the lower speeds to achieve comparable airflow numbers. That is, they may be enough. This is not a rule, but an advantage that may or may not be exploited. Of course, it also depends on the geometry of the fan in question, and the Stratus has a really efficient one. You already know this from the Fluctus 140 PWM tests, which the Stratus 140 PWM fans are based on in terms of shape.
The difference between the Stratus and Flucus series is mainly in the presence of teeth on the leading edges of the blades, which are smooth in the cheaper fans. And that’s why the Stratus 140 PWM achieves lower airflow (than the Fluctus 140 PWM) at comparable noise levels. In fact, Stratus 140 PWM fans have slightly higher tonal peaks in the critical band. These are at or near the same sound frequencies, but the Stratus 140 PWM is noisier and rumblier. And that’s basically across the entire speed range, including low speed, where even in the quietest measured mode, it is approximately 5.7 dBu (at 104 Hz) noisier than the Fluctus 140 PWM.
Because of the noisier low frequencies, slightly lower speeds are also associated with the Stratus 140 PWM fan in noise-normalized modes, which naturally results in a lower measurable airflow (we’re still comparing to the Fluctus 140 PWM…). At comparable speeds, it is virtually identical though, as the geometry of these fans (Stratus 140 PWM and Fluctus 140 PWM) is not too different. But the Stratus is a bit noisier in the lower frequency range. Overall, however, it can be said that compared to the older models of the Polish manufacturer, still under the SilentiumPC brand, there is a noticeable improvement in terms of features around the motor. In the case of the Stratus 140 PWM, there is no rattling like with the Sigma Pro 120 PWM (also known from the Fera 3/v2 cooler) anymore.
And the Stratus 140 PWM even supports semi-passive mode, where the fan switches off at a certain PWM duty cycle. At the same time, however, very low minimum speeds of around 300 rpm are maintained. These are remarkable features for such a cheap fan.
For those interested in high cooling performance, the downside may be in the relatively lower top speeds around 1200 rpm. Even at maximum speed, the Stratus 140 PWM’s airflow is only average, even from the perspective of 120mm fans. But this again at a lower-than-average noise level. This (always relatively quiet operation) may not be of interest to everyone, and you’ll have to look elsewhere for super-powerful 140mm fans.
We can write about the Stratus 140 PWM as a balanced solution. This is also in terms of the application scenarios for which this fan is suitable. High efficiency (with a great ratio to cost) is achieved in a non-restrictive environment, on radiators of liquid coolers, grilles or a dust filter. The results are always only average, but considering that it is one of the cheapest 140 mm fans, the Stratus 140 PWM does not perform badly at all.
It will be important to see how the Arctic P14 stacks up against it, however, which is also expected to be noisier at lower sound frequencies. This is what will put many low-end fans with modern geometry at a bit of a disadvantage, but it is, of course, a trade-off. The recipe for quieter low frequencies exists, but it comes at a cost. Still, the Stratus 140 PWM is a very decent, versatile inexpensive fan that’s definitely worth having on your radar. Especially when you’re looking to keep the purchase price as low as possible when outfitting a computer build with a cooling system.
English translation and edit by Jozef Dudáš
| Endorfy Stratus 140 PWM |
| + Suitable for every use case |
| + Very low price... |
| + ... and an extremely attractive price/cooling efficiency ratio |
| + Cooling efficiency (airflow/pressure per unit of noise) at a high level... |
| + ... beats even the top-notch 120 mm fans |
| + High efficiency even with plastic dust filters |
| + Wide speed range plus passive operation |
| + Very low speeds possible, stable from approx. 297 rpm |
| + Virtually noiseless operation of bearings and motor |
| + Extremely low, negligible vibrations in terms of the frame |
| - The sound is characterized by rumbling frequencies. For some, they may be unpleasant |
| - Weaker maximum airflow due to lower speed... |
| - Possible collision with a nylon dust filter |
| - Key parameters, airflow and static pressure, are missing from the manufacturer's specifications |
| Approximate retail price: 8 EUR |
- Contents
- Endorfy Stratus 140 PWM 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
stratus 14 is more expensive than arctic p14, therefore it’s not cheap.
It may or may not be. It will depend on the specific store you are shopping at. Somewhere the Stratus 140 PWM fan may be more expensive (probably especially in the US?), somewhere else it may be a bit cheaper.