Closed Edge Axial Fans, Why Are They Less Used?

Graphics cards have evolved quite a bit over the years. You only have to look back 10 years to see this evolution, but currently they face a basic problem: improving their cooling. To achieve this, some brands have put on the table a solution that has been used for a long time in PC: closed-edge axial fans . What are they, how do they work and why are they hardly used today?

There is hardly a brand that uses this type of fan, ASUS, but in the PC world we do have some more like Noiseblocker, which have taken this type of fan to the extreme, which is widely used in the professional industry.

Closed Edge Axial Fans

Very noticeable performance improvements

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ASUS calls this technology Axial-Tech, but since it is not a patent itself but a concept, each one will end up calling it whatever they want within their idea of it. Therefore, we will borrow the name of the term in ASUS to refer to its concept for its RTX and explain its fundamentals.

As in the case of Noiseblocker, what is intended with this series of fans is to increase the flow rate, the static pressure and reduce the loudness. To do this, and taking into account the same fan diameter in two hypothetical usability cases where Axial-Tech and a common fan confront each other, with the former the length of the blades is precisely taken to the limit, where the size of the structure that supports it.

These improvements are key to adding a kind of “ring” that is commonly called a closed edge. This ring has several advantages, since in the first place it increases the structural resistance of the whole assembly and by being able to make more aggressive turns in the angle of attack of the blades, it is possible to improve the air pressure on the GPU heatsink.

Closed axial fans: higher rotation speed and lower noise than a common axial fan

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Given this and as it happens in the NB-eLoop, the advantages do not end there. Greater structural rigidity allows the fan to rotate at a higher speed on its axis and at the same time allows optimizing its frames to reduce noise.

This is a very complex engineering job, since we speak of quite a few revolutions per minute in a size of 9 or 10 cm, depending on the manufacturer, where the final width of the blade is not too large.

In addition, it has to be studied in conjunction with the heatsink itself, since it allows a greater use of its surface, but also a higher density of fins in it, which enhances cooling and requires at the same time a separation of they are optimized so as not to represent an increase in overall loudness.

Given its advantages, the question is obvious, why is it not used more in current GPUs? Mainly because of development costs and secondly because many manufacturers think that the advantages do not outweigh the general disadvantages for a graphics card.

The set is important, not just the fans, so each model must be optimized in its concept for this purpose and this takes time. But like any technology or fashion, if in the end it works in more than one design and is implemented well, everyone will copy what they have seen to equalize the contest and these closed-edge axial fans will be no exception.