Arctic P12 PWM PST: The most famous rumbling fan

Arctic P12 PWM PST in detail

There are a lot of droning or downright rumbling fans out there, but none have been as popularized by this sound profile as the Arctic P12. Probably also because this acoustic deficiency is really pronounced here and has pushed the manufacturer to make design changes in newer models that are aimed at suppressing critical tonal peaks. But even so, the base model P12 PWM PST is a remarkable fan and is unbeatable in its price range.

Because of its extremely low price and high “cooling efficiency”, the Arctic P12 PWM PST is the best-selling 120mm fan by many metrics. With a large number of owners, there is thus naturally a fair amount of feedback, and since most people’s hearing is fine enough to hear this fan’s sound profile more acutely, there are often voices that this fan is noisier. This is because of the tonal peaks not only at the lower “rumble” frequencies, but also at the middle “hum” frequencies. We’ll get to that as we go along and flesh it all out in detail.

Starting out, it’s still worth noting that the Arctic P12 compares with the previously tested BioniX P120 A-RGB, although it has seemingly the same rotor – it doesn’t. And there are more than enough differences, including a shorter tunnel (P12) with less rotor clearance from an obstacle, but let’s start the analysis as usual from the top.

The P12 PWM PST fan (hereafter referred to as the P12, but we’re still talking about the PWM PST variant) has a 5-blade axial rotor, which is typical of Arctic’s current “P” series models. Because of the small number of blades and the intention to achieve high static pressure, each blade must be large. If the blades were smaller, a lot of air would escape through them, which would reduce the airflow the more resistance the fan would have to overcome. Thus there is a considerable cross-sectional area covered by the blades, so that the airflow does not decrease excessively even if the fan is operating on restrictive obstacles.

The leading edges of the P12 are significantly curved so that the air streams have a cylindrical trajectory and more effectively avoid contact with the frame. Also at this level (due to lower friction and less turbulence), there is an increase in efficiency compared to traditional fans that do not have such significantly curved blades. But with the P12 it is really extreme and the leading edges of the blades have up to 60 mm. That’s still 5mm more than the BioniX P120 A-RGB.

The thickness of the material goes up to 3.5mm in critical areas (towards the tips), but even with those, they are flexible and prone to higher vibrations when using PBT materials (and even a stronger LCP wouldn’t completely save it). And these, when they hit the resonant frequencies in an exemplary way, the result is that at the same, let’s say, average noise level, the P12 can indeed be a noisy fan both in the low-frequency (up to 200 Hz) range of sound and between 300–450 Hz.

One of the differences from the BioniX P120 A-RGB that is also good to notice when judging the results is the smaller offset of the rotor from the frame. The P12 has a half centimeter narrower tunnel, so the rotor is closer to the obstacle, which changes the airflow velocity in addition to the noise. So there is actually a similar effect that the Noctua NA-IS1 frame is supposed to provide.

For being only a 6-euro fan, the precision of production is extremely high. It’s only at the level of really fine detail that you’ll find that the P12 has slightly looser manufacturing tolerances than Arctic fans with a similar rotor. There will be a tiny unevenness here and there on the P12, but it will have virtually no impact on the performance. And at this price range, it’s also a bit unfair to point it out, as similarly priced fans often fare considerably worse.

The design of the frame of the P12 is very simple and differs from the others only by the shaped protrusions in the corners where you would expect anti-vibration pads. Arctic doesn’t supply these with this fan, although they would be useful. But again, considering the price, this is something we can’t fault this fan for. In short, a necessary compromise.

Also simpler on the P12 is the sticker with the Arctic logo in the middle of the rotor. On the BioniX P120 A-RGB and the BioniX P120 individual characters are protruded and here (on the P12), they’re “2D”. Of course this is a minor thing, but we are talking about visible differences compared to more expensive models…

The cable is “ordinary” but solid – flat, with the wires holding together nicely. There are two connectors at the end. One to connect the fan to the motherboard or hub/controllers, and the other to daisy-chain another fan. The cable is 40–45 cm in length.

The Arctic P12 (PWM PST) is a 120mm format fan with a claimed speed range of 200–1800 rpm. You can choose between very low noise and medium performance. The bearings are the fluid (FDB) bearings that Arctic uses in their fans outside of the CO (ball bearing) variants.

Note: Specifications chart, which used to be in the following place, is now on the second page of the article. We have reserved a separate chapter for it because of its growing size and already relatively large height. This separation should thus contribute to better user control, especially on mobile devices with smaller displays.

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Arctic P14 Max: The best yet? Well, it depends…

The culmination of our trilogy of tests of Arctic’s 140mm fans is here. With the P14 Max, the designers have worked on improvements that change both the acoustic properties and performance of the fan. The main new feature, the hoop, allows for, among other things, a significant speed increase, due to which this fan can have a really high airflow. On the other hand, fans of extra low speeds will not be too pleased. Read more “Arctic P14 Max: The best yet? Well, it depends…” »


Arctic P14 PWM PST CO or ball vs. fluid bearings

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 (P14). 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. Read more “Arctic P14 PWM PST CO or ball vs. fluid bearings” »


Arctic P14 PWM PST: Unbeatable in its segment

What is fascinating about the Arctic P14 is the particularly high contrast of price to (cooling) efficiency. These fans are among the cheapest, while at the same time achieving top results with respect to all 140 mm fans in terms of airflow per unit of noise. And that’s even through obstacles. Arctic has made almost the maximum out of the funds available to produce the fan, and it is definitely worth it. Read more “Arctic P14 PWM PST: Unbeatable in its segment” »


Comments (25) Add comment

  1. And one addendum for the discerning reader who will scroll through the comments here and there and might ask the same question as one of the readers of this article in another language. Namely, why the BioniX P120, being more expensive, often achieves a lower airflow than the P12. We discussed a bit in the opening chapter that these fans don’t have the same rotors, but I didn’t want to pay any extra attention to that in the conclusion (these aren’t fans that are in any way competing or that you’ll be deciding between).

    An explanation why the BioniX P120 often ends up below P12:

    The P12 has larger blades compared to the BioniX P120, although it doesn’t seem like it unless one sees those fans side by side. So with the same size hub, the gaps between the blades are naturally smaller on the P12, so there is less room for airflow leakage and higher static pressure is achieved. This means that the airflow loss due to obstacle resistance is smaller with the P12 than with the P120.

    At the same speed, the P12 has all the ingredients for higher airflow across all use cases. If the BioniX P120 catches up to the P12 anywhere, it’s when the P12’s sharper tonal peaks significantly limit the P12 when the speed is controlled for equal noise level.

    1. Next question then is why is Arctic still making and selling the BioniX P120? It is more expensive, performs worse, thicker, and does not even have RGB to justify the price difference. Perhaps the P12 was released after the P120 as the cost and performance optimized version?

      Another curious observation is how Arctic is the only company using a 5-bladed design. It is only using PBT yet it can compete with some of the best 9-bladed LCP designs out there. Why aren’t there other companies trying to use a similar rotor design? And would an LCP version of the P12 be any good?

      1. Good questions. I don’t know in what order the individual Arctic P fans came out, but anyway the BioniX P120 A-RGB has a different rotor compared to the BioniX P120 (which has the same rotor shape as the P12). The shorter blades of the BioniX P120 A-ARGB are probably due to the implementation of the circular lightguide, which narrows the overall cross-section a bit, which the BioniX P120/P12 rotor would not fit into. I suppose this is the reason Arctic pushed the lighting more with the BioniX P120 A-RGB at the expense of a slightly smaller cross section with a slightly smaller rotor. The side effect is that the blade geometry of the BioniX P120 A-RGB does not achieve the same pronounced tonal peaks as the P12. This could also be the focus of why the BioniX P120 A-RGB is structurally a bit different.

        It is hard to say how the characteristics of the P12 would change if a rotor made of LCP were used while maintaining the same geometry. LCP is stiffer, but the blades of P12 are really long and even with this material there will be some vibrations at their tips. The fact that they will be smaller does not automatically mean that the tonal peaks will be lower. Of course this is highly probable, but I can’t say for sure. If the P12 blades were glass, this fan wouldn’t give other fans much of a chance, but again, only until it breaks. 🙂

        1. Interesting, I could not notice that the A-RGB and regular version of the P120 has different rotor shapes. The pricing from Arctic makes more sense then.

          I guess the difficulty in suppressing the vibrations is why few companies use a similar 5-bladed design. The 9-bladed design does not perform worse and more easily avoids the vibration issues. Looking forward to seeing your review on the ringed variants of the 5-bladed design to see how far this design can go.

  2. > But on a thicker radiator in one of the model situations, the Arctic P12 ranked as high as just behind the Noctua NF-A12x25 PWM.

    well, it did once the noise became high enough to make all the finetuing Noctua does irrelevant, at 31dB(A) and below there’s no competition, and I hope we’ll see these lower noise targets soon

    that being said: for a technical/mechanical room it’s an amazing option, it’s dirt cheap, has great performance when you have some decent soundproofing of said room and can be just left unattended for a reasonable periods of time, it’s a product so vastly different I don’t think it even makes sense to compare it to A12x25, at such high noise levels basically the only selling point of A12x25 would be reliability and customer service, but most users would probably prefer to buy a 5-pack of P12 instead (and you should note multi packs are even cheaper than the regular price!) and still have enough cash for like 2 more of these

    1. “well, it did once the noise became high enough to make all the finetuing Noctua does irrelevant, at 31dB(A) and below there’s no competition, and I hope we’ll see these lower noise targets soon”

      Unfortunately, I cannot agree with this statement even now. The extra details that Noctua has often stand out more with relatively higher speeds. Whether it’s Flow Acceleration Channels, Stepped Inlet Design, a significant narrowing of the gap between the blade tips and the frame or Inner Surface Microstructures. These elements counteract the shortcomings that become stronger with increasing pressure. The fact that the NF-A12x25 gives excellent results at low speeds is largely due to the fact that the operation of the motor and blades does not create any noise, so at this level there are no such pronounced limitations as with other fans, and the NF-A12x25 fits into the same noise level at higher speeds.

      I confess that I am a little frustrated that I cannot satisfactorily explain to you that 31 dBA as we measure it in our procedures represents an extremely low noise level. Certainly, for example, the NF-A12x25 PWM speeds are circa + 280 rpm compared to what is acoustically suitable for you as a user with extremely sensitive hearing, but the fact that these are noise levels suitable for noisy technical rooms is a misjudgement and such a presentation will be highly confusing to the vast majority of people.

      1. at high enough noise levels the difference between P12 and A12x25 that costs as much as 5-pack + 2 of P12 obviously still exists but doesn’t justify the price difference for most users and that explains the popularity of P12, being “slightly behind” even the best of the best even in a single noise-normalized test is a big feat and more noise tolerant people just won’t see the point of A12x25, or any other “quiet brand” in general, and explains why people were pretty happy with “Silentium”PC too as their products were probably a class below P12 but still within their acceptance range

        what annoys me are people claiming something is inaudible and amazing when it’s not, there’s an important difference between “I’m happy with this product” and “it’s great, there’s no point getting anything more expensive”

        1. I do not claim that NF-A12x25 PWM is at 787 rpm (i.e. the speed in our “31 dBA” mode) a noiseless or soundless fan, I am just trying to balance it a bit. At this speed you write about industrial noise or use in noisy technical rooms, which is misleading. I respect that in your idea of quiet operation the NF-A12x25 PWM has an even lower speed.

          Now I know, 600 rpm, okay, and as a sign that I appreciate that we have such demanding readers, I promise you that sooner or later we will create another mode, which will be twice quieter than the quietest mode that we have now. In addition, we will select fans that will have the highest airflow in the 31 dBA mode and there will be room for further noise reduction. Some fans cannot be slowed down even to 31 dBA mode and of the remaining ones, half of them have a speed of 600 rpm or lower. The NF-A12x25 PWM here allows setting some of the highest speeds mainly because it is PWM controlled, and now I’m not afraid to use the word extremely quiet running of the motor and bearings. This is also visible in the spectrograph, where in the frequency band of these components the noise is extremely low. Noctua deserves all the respect in the world here for going into such details as smoother/quieter PWM waveforms with a slanted left-hand side of the pulses.

          Therefore, in situations where the NF-A12x25 PWM can benefit from high static pressure, it has a good lead from other fans in its format. In non-restrictive environments at low speeds, DeepCool, which has the advantage of a larger outer cross-section of the rotor or rather larger blades, plays a more equal game.

          1. the last comment wasn’t directed at you specifically, but many other reviewers do make such claims (deeming Ninja 5 “too quiet” was probably the most extreme example, and coming from a source that can and often does a great journalism was simply a disappointment, “fortunately” I already had one due to similar reviews so it wasn’t their “fault” that I purchased it, but the aftertaste of that review certainly wasn’t good)

            regarding A12x25 bearings and motor, when close enough I can hear slight clicking/ticking that is absent both in SilentWings 3 and NB B12, but it’s quiet enough to fade out at a distance and other sources of noise (mostly “wind” in SilentWings and what I’m assuming is a motor hum/whine in B12) quickly get above my tolerance threshold (at the actual use distance, not just playing with a fan next to my ear) while the performance stays behind A12x25

            1. Is what you describe (clicking/ticking) in NF-A12x25 with PWM control? At low speed with DC control the motor is noisier. When I look into the spectrograph of the NF-A12x25, I don’t see such noises with PWM control. There are small peaks at 1567 and 1974 Hz, but both are too narrow for some “clicking” sound and for example the mentioned Silent Wings 3 seems to me at very low speeds noisier even subjectively. And the spectrograph also points to more noise in the motor/bearings band (850–2500 Hz). Of course, if we are talking about NF-A12x25 with DC control, it changes the situation – Noctua has this fan optimized for PWM, with linear power supply it is worse especially at low/starting speeds. We found this out five years ago, where we wrote about “slight clicking” at 268 rpm for the ULN variant (NF-A12x25 with DC control), in contrast to the “clean” operation of the PWM version (with PWM control). Take a look at it, it could be the control… or maybe you own some 3-pin variant of NF-A12x25 (ULN/FLX)?

              Under the above mentioned circumstances, when the NF-A12x25 starts to click, whirr or make some non-aerodynamic sounds with decreasing speed during DC control, the efficiency of this fan will also drop in the same noise level. When setting fixed dBA, the sound will be largely made up of unwanted noises, which have an undesirable impact on the final rotor speed when tuning (the noisier the motor, the less room is left for rpm).

              1. it’s regular PWM, and as mentioned these are quiet enough to fase out at a distance, probably arms length is already enough and it never becomes audible from the actual use distance no matter the speed, it may be some artifact caused by a low PWM setting, maybe slightly flawed PWM controller on the board too as I imagine that may cause trouble

                with SilentWings it always went from inaudible to the air woosh sound without any other sounds for me

                1. Then it’s very strange. We use spectrograms instead of sound recordings for sound analysis precisely because we do not want a dispute to arise at the level of subjective perception of individual frequencies. Everyone sees their intensity in spectrograms in the same way and the results of NF-A12x25 PWM clearly show that there is practically no noise that can be perceived by a person when using PWM control. Or if you can hear some sound in the frequency band we are talking about, you should also hear it with Silent Wings 3.

                  The signal quality of the motherboard/hub should not make a difference in noise, it is determined by the NE-FD1 IC inside the fan. Noctua often has complaints about the PWM signal quality of third party devices and states that it can be misinterpreted at lower speeds. But this is not the case with Noctua fans and it should not affect the noise level anyway, as long as the fan is running stable at the given speed. The misinterpretation of PWM that Noctua mentions is that the fan operation may not correspond to the set PWM duty cycle (we have discussed this in more detail in this article, where we also discuss the key features of the new Noctua NA-FH1 hub).

                  But there must be something to it, why the fan NF-A12x25 PWM “clicks”
                  … I can’t yet find the reason for this. Someone could write that it is a faulty piece, but that is not likely (and I assume that you observe the same behavior across several pieces)…

                  1. it may be some driving issue at particularly low speeds (even with all the attention to detail Noctua has they want to make money at the end of the day so I’m sure such extremes are less polished than the 80% or even 95% of users would use), it doesn’t bother me, just an observation of behavior at low speeds

  3. Noctua NF-A12x25 beats Arctic P12 when it comes to silent PC cases like Nanoxia Deep Silence 8. The lower frequency of P12 is much harder to stop. With mesh cases, a lot is up to personal preference (apart from CPU cooling where NF-A12x25 shows its teeth).

    The 80Hz peak is exactly as I measured. I don’t remember other peaking frequencies, but 1 kHz and the following harmonic peaks each full kHz are a case of USB interface noise. It always exists, but rarely to this extent.

    1. Tonal peaks around 1 kHz are certainly not determined by the USB interface. They appear only with some fans and even then very rarely. If the peak is relatively slimmer/sharper (and lower), it is mostly about the sound of the bearings. More and wider taller peaks then usually represent the motor whirring. A nice example of this is the Cooler Master SickleFlow ARGB fan (spectrogram) or even the older SilentiumPC Sigma Pro 120 PWM fan (spectrogram).

      Which peaks show up and how will also depend on the conditions in which they are measured. We also focused on this aspect when building the methodology back then (designing the acoustic panels and calibrating them before measuring each fan), so that the environment is not only consistent, but the resolution is as high as possible.

  4. Amazing reviews ! Good job !
    I appreciate the true honesty toward this fan unlike youtubers or other reviewers that praise this fan without mentioning the terrible whine it does at too many rpms. I have it and it’s the fan i hate the most out of all the fans i ever got. Could be good for deaf people though.

  5. Thank you very much for the impressive, comprehensive review on this part.

    One question from me that is still remaining:
    Did you ever get the chance to look at the Arctic P12/P14 PWM PST CO (=Continuous Operation) version of this fan?

    They feature a dual ball bearing instead of the fluid dynamic bearing from standard P12/P14 at rougly the same unit price, with the major market difference that the CO versions are not offered in cheaper 5-packs.

    Over the years, I’ve read several anecdotes from users about the humming issues being less prevalent on these models, but so far no reviews from anyone with the necessary expertise and equipment look into it in more depth. Would be great to know if there could be similarly priced parts without the acoustic drawbacks.

    1. In the variant with ball bearings we will test P14 (PWM PST CO).

      As far as the difference in noise between the variant with fluid and ball bearings is concerned, there can be some, of course, but only at the level of the bearings. For these fans, the critical point is the level of the blades, or rather the tonal spikes, which arise based on the nature of their undulations (and catching resonant frequencies). This will be the same regardless of what bearings the fan uses. Fewer reactions to the “rumble” of the CO variant could perhaps stem from the fact that it is probably a less widely used fan, owned by fewer people, so there will be less feedback/less negative criticism of the acoustic properties?

      1. I think testing the P12 CO will be very interesting at least from an academic standpoint. It will help answer the question “By how much does bearing influence characteristics of the fan other than the bearing noise?”

        1. Yes, that’s a very good idea. But shouldn’t we rather do it with P14 (PWM PST vs. PWM PST CO)? After all, we have less 140 mm fans in our database (and we want to have the new 140 mm Noctua LCP fans as dense as possible, of course). This knowledge will tentatively be transferable across 120/140 mm formats, since the speed difference between them is quite small.

          1. I agree that instead of testing the P12 CO, testing both P14 and P14 CO would be a good idea. It’ll help answer the same question while bringing more results to the 14 cm fan database.

  6. Are we going to see Phanteks T30 tested at some point? I know it has a thicker body but many users can still fit it which makes it a direct competitor to 25mm fans. You have the best testing methodology and reporting that I know of so it would be great to see this product tested too – from other reviews it seems to be a good performer.

    1. Of course we will test the Phanteks T30, we will test all fans gradually. And the key model, of course, will not be missing. But we are trying to add individual fans to the tests in a way that makes the most sense from several points of view. But don’t worry, you won’t be deprived of the T30 analysis and I would say that it’s quite close. 🙂

  7. Do you know the difference between Rev.1, Rev.2 and Rev.3 of P12 PWM PST?
    I recently bought the value pack of P12 PWM PST and I couldn’t find any rotational speeds that makes the resonant noise. On the package of it, there is the text “Rev.3” which will mean the second revision of P12s.

    I tried to find the information about this and I found that the company resolved the resonance at Rev.2. Also there are a the change at required current(0.08A->0.10A). But I don’t know the difference between Rev.2 and Rev.3.
    I also questioned this matter at Arctic. They make the silent revision on their product so frequently.

    1. So I must admit that I missed that there are also different revisions of the P12 PWM PST. In this case, ours, tested, will be the rev. 1. – 0.08 A and without the revision specified next to the EAN code. That’s how Artcic usually does it when it’s the first revision…

      … unless the rotor design has changed, I personally cannot figure out why the tonal peaks should disappear or at least get to a significantly lower level. Well, we’ll have to ask them what the differences are between the revisions. So on the face of it, the rotor looks the same, as long as the illustrations on Arctic’s current web site are consistent with it. It occurred to me that it might be different, a more rigid material structure with lower thermal expansion. But that would add to the manufacturing cost and probably would be unprofitable at the same low price?

      But I understand the increase in motor power. I would say the original P12 is quite significantly underpowered, with small headroom.

      Anyway, very good point and I’m off to find out how it is with these revisions. Then, when I get some information, I’ll share it here, of course. 🙂

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