Arctic P14 PWM PST CO or ball vs. fluid bearings

Evaluation

Longer life in exchange for more noise? These are also some of the agenda items we’ll cover in our comparison of the Arctic P14 CO fan with the fluid bearing variant. These are actually the main points. In any case, the ball bearings in the more expensive variant of these fans also have specific features that can be easily observed and distinguished even in normal, “home” use.

Evaluation

Were it not for the existence of the Arctic P14 with fluid bearings, in many scenarios we’d be writing about the P14 CO as the most attractive low-cost option for the desktop as well. This therefore remains the P14 (without “CO” in the designation). Not only because this variant is slightly cheaper, but also because it is quieter. Again, don’t imagine that the P14 CO is significantly noisier, but there is a difference between the sound of the bearings. The friction of the ball bearings (P14 CO) is obviously higher (than with the FDB in the P14), which is also indicated by the power consumption results, which are slightly higher at comparable speeds.

Friction (of bearings of all contact types) is, of course, dependent on the particular lubricant used, and certainly some ball bearings can have lower friction and higher energy efficiency compared to liquid bearings. This is not the case with the P14 CO though, but even so, the airflow per unit of power consumption is above average. But let’s move from the marginal to the essential.

Due to the slightly higher noise level of the P14 CO bearings (compared to the P14) lower speeds are achieved at comparable noise levels, which are then naturally coupled with a lower airflow. The lower the normalized noise level, the more pronounced the difference, as the bearing noise makes up a larger proportion of the total noise. From this point of view, P14 COs are relatively unsuitable for systems where you are counting on very low speeds. That is, unless the fan will operate with excessive ambient pollution, where the CO variant could have the upper hand in terms of durability. That’s even the case compared to the competing Endorfy Stratus 140 PWM fan. The latter is cheaper, but the lower price is related to the weaker cooling efficiency, which (in the case of the Stratus 140 PWM) is lower even in a situation in which the P14 CO achieves its “worst” results. However, this is no longer the case for the more expensive Endorfy Fluctus 140 PWM, which already has the edge over the Arctic P14 PWM PST CO in this aspect.

With higher speeds, in modes normalized to higher noise level, the P14 CO is already slowly catching up to the P14 (i.e. the fluid bearing variant) and the Stratus 140 PWM is by then already quite far, far behind. With obstacles, with which noise increases at multiple frequencies, the differences between the P14 and P14 CO are already almost blurring, for example with a plastic dust filter. And on the hexagonal grille, the P14 CO ranked right at number two in the results database, behind the P14 with FDB. Naturally, these are already top-notch results that surpass even high-end 140 mm fans, which include the BeQuiet! Silent Wings Pro 4 (BL099). The relative placement on radiators is above average, and again, for clean environments where you can’t expect much practical benefit from ball bearings, the Arctic P14 fans with fluid bearings make more sense.

The increase in noise caused by ball bearings is in the 4–6 kHz range (a kind of… rustling). However, we feel it is again important to point out that the differences are very small and for most (even more demanding users) are negligible. Especially when we’re still in the segment of cheap fans, where the acoustic performance requirements should be lower overall.

We already wrote about the surprisingly low vibrations that get to the frame last time, with the P14 (PWM PST). In the case of the P14 PWM PST CO, the vibrations are even lower. They are so low that they are below the resolution limit of our sensitive measurement system. From 1350 rpm downwards, nothing but “zeros” were measured in all axes. And that’s across multiple samples. It is thus possible or probable that the ball bearings used are more precise. And apparently their higher friction does not necessarily change that either. Thanks to the recording of such low vibrations and simultaneously higher tonal peaks (which, at the same speeds, naturally remain the same as those of the P14), one new insight emerges here. Namely, that the vibrations on the blades are too low to be transmitted in a greater intensity to the body of the frame. Nevertheless, they can still make the material of the P14 (CO) resonate significantly. In any case, the P14 CO should not be a source of secondary noise caused by vibration transfer from the fan to the contact structure (case, cooler, case through cooler, …).

The price-to-airflow ratio is very attractive. Of the 140 mm fans tested, only the Arctic P14 PWM PST and Endorfy Stratus 140 PWM are better in this respect, but they both have the assumption of lower durability in adverse conditions (e.g. in server or industrial environments?) with excessive pollution or excessive temperature. These are also the reasons why the Arctic P14 CO still deserves the “Smart buy!” award. What do you say?

English translation and edit by Jozef Dudáš

• Contents
• Arctic P14 PWM PST CO 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