Some tower CPU coolers use two fans. The front one that pushes air into the fin stack and a rear fan that pulls it through. This push–pull setup improves the efficiency of heat removal from the heatsink and can lower temperatures by a few degrees. You’ll find the same idea in the new generation of graphics cards from Asus and Gigabyte. Here, we look at how a fourth fan affects noise levels and temperatures on the Aorus GeForce RTX 5080 Master 16G.
If you’ve read through the previous chapter, it’s probably clear to you that the fourth fan provides the most significant benefit when it runs at significantly higher speeds than the trio of fans on the cooler. It can then lower the chip temperature by several degrees. If the trio of Hawk fans is running at minimum speeds, the supplemental fan at its maximum 1800 RPM can lower the average chip temperature by about 6 °C. However, the noise level increases so much that it doesn’t make sense.
If you want to achieve a noticeable benefit without the card becoming louder, you will have to stay near its minimum speeds—in the range of around 800–900 RPM. At these low speeds, you must also keep the trio of fans on the cooler running slowly. But this means you will have to manually tune the curves for both the supplemental fan and the trio of fans on the card. The result will be that, in the area of minimum fan performance, you will lower GPU temperatures by roughly 1–3 °C.
This fundamentally doesn’t differ from the experience we have with supplemental fans on CPU coolers—with the difference that for CPU coolers under synthetic load, temperature differences are easier to measure.
However, if you prefer higher fan speeds and lower GPU temperatures, the fourth fan’s benefit becomes much smaller—the temperature differences we measured in the mid-RPM range were often lost in normal fluctuations. In a gaming build where a demanding title is dumping nearly 500 W of waste heat into the surroundings, it’s hard to keep the load and temperatures stable enough for the effect to show up clearly in the readings.
English translation and edit by Jozef Dudáš
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