Fractal Prisma AL-12 PWM ARGB case fan tested – good fan for case and radiator, even at lower speeds

The Fractal Prisma AL-12 PWM ARGB is obviously underestimated as a 120 mm case fan, because we have now received several requests from the community to test this model in more detail. Most of the reviews of the cooler that we could find at all were pretty bland and came from the “laying on of hands” and “beautiful” categories. That was reason enough to take a closer look at the whole thing.

For currently a good 23 euros, this ARGB fan is already an offer from the slightly higher price segment, but still cheap if you sort the top models in the right price and the fan does what you say it is. With its 25 mm thickness, the fan is exactly within the norm, which of course also makes it more comparable in the end, especially since the rest of the design tends to follow current trends and at first glance does not reveal any daring design stunts.

Only the fan and 4 screws are included, but that’s enough because the RGB fans can also be cascaded. When it comes to bearings, you rely on a classic plain bearing, which you want to give better running properties with an additional magnet. We’ll see later if and how this works. In the end, the marketing term “LLS” means nothing other than “Long Life Span”, i.e. a bearing with a higher durability (MTBF). But it already sounds good, goal achieved.

Let’s take a look inside the open fan. We recognize a classic 4-pole motor, the control board with a total of six LEDs, the cable feeds hidden in the hollow (and somewhat thicker) motor strut and the simple plain bearing with loads of corresponding bearing grease. Everything is pressed in and placed on the simple but very torsion-resistant frame structure with a total of 4 engine struts.

The rotor as the counterpart to the stator is a translucent block with a total of seven rotor blades, slightly rounded and beveled edges and corners as well as the obligatory, pressed-in ring magnet as rotor and the axis made of stainless steel. The translucent fan blades and the outer ring fitted into the frame were specially designed for uniform lighting, which compensates for the relatively low number of LEDs and avoids visible light spots. The ARGB control supports the normal, digital 5-volt connections of the mainboards and thus also Asus AURA, Gigabyte Fusion, MSI Mystic Light, ASRock Polychrome and other systems that are based on the same technology.

Everything is carried by a black, simple frame that does not hide any secrets at first glance. The PWM-controlled fan creates a speed range from 500 to 2000 rpm and does not offer a semi-passive mode (i.e. no fan stop) with PWM control (20% minimum). The decoupling with the fully attached rubber corners is well solved because it does not twist when the screw is tightened. The gaps and surface finish are good. The power consumption is exemplary low at full speed with less than 2 watts for the fan (without ARGB).

First of all, there are two things to criticize that do not reduce the quality and performance of the fan, but are based on a contradiction between the data sheet and reality. While the static pressure fits almost exactly, the CFM values ​​for the volume flow are a pure marketing invention, which also lacks a physically plausible basis, because the reality is 28 percentage points below the imprint. And then there is the indication of the minimum speed of 500 rpm or 20% PWM. If so, then in purely mathematical terms that would be 25% PWM and in reality it is even 550 rpm and 27.5% PWM.

But I’ll get to that in a moment, because DC voltage-controlled these fans are a smooth stunner, without the marketing even mentioning it. Exaggeration and understatement are superbly balanced here, so we also forego deducting points. Only that with the CFM values ​​definitely needs to be corrected. But first of all the data sheet again for better comparability with the later measurement results:

On the next page you can see how and what we test and why. Understanding the details is extremely important in order to be able to classify the results objectively later. The differences between many models are more in the details and the best fan for all situations can hardly exist. There is a certain optimum in every situation and of course there are also good all-rounders. But they usually have their price. If you are planning specifically with 60 mm radiators, for example, you can perhaps save money by choosing the best model for your application, which might not do so well as a case fan. And vice versa, of course.

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