In a nutshell: YouTube channel Major Hardware has taken PC cooling to an extreme by turning a case's side panel into a 3D-printed "Superdome" packed with 15 Noctua NF-A12x25 fans. In tests, this custom airflow assembly replaces the standard panel and cuts CPU temperatures by a wide margin.

In place of the usual tempered glass, the Superdome forms a bulbous structure that concentrates intake across the entire flank of his Lian Li O11 case, effectively turning the side panel into a dense grid of pressure-optimized fans. The design is a direct response to viewer feedback on his prior Fanhattan Project, which used a dome of tiny fans and led viewers to ask for a version built around full-size Noctua NF-A12x25 120mm fans.

"I dropped about 20°C just by putting the Superdome on the front of my PC," the TechTuber said during testing. "This is pretty incredible, and it's not even loud."

The Superdome grew out of a viewer-inspired challenge. After showcasing the Fanhattan Project, comments rolled in urging him to try the same idea with full-size fans. Each NF-A12x25 retails for around $40, bringing the total well past $600 – until Noctua stepped in to supply the hardware, along with matching spools of 3D printer filament for the custom housing.

Major Hardware then designed the dome to fit 15 fans: one at the top, surrounded by five in the midsection and nine forming the base ring closest to the PC case. The intricate design had to balance symmetry, airflow, and the limitations of his 3D printer's build volume.

Printing alone consumed several days. Using Bambu Lab H2D and H2S printers, he managed to fabricate the dome with minimal splitting, though the process pushed his tools to their limit. The result, once assembled, resembled a compact wind tunnel – a spherical surface of spinning Noctua blades feeding directly into the computer chassis.

Once mounted to the side of his Lian Li O11 case, the Superdome transformed the system's airflow. All 15 fans were configured as intakes, creating noticeable positive pressure inside the case. "Honestly pretty quiet," he observed, though he admitted that cable management was "a little bit of a disaster." Any cable shift near the blades could turn serenity into chaos.

Testing with Battlefield 6 provided stark results. Using a standard glass side panel, CPU temperatures topped out around 86°C, as measured through AMD's Ryzen Master software. Swapping the glass for the Superdome dropped temperatures to roughly 67°C under identical conditions. The cooler readings are largely due to how much fresh air the dome pulls into the case. Sitting next to the setup, he noted, produced "a constant breeze."

The Superdome's significance extends beyond one creator's build. By publishing the 3D-printing files on Thingiverse, Major Hardware effectively opened the design to the broader maker community. Anyone with a compatible Lian Li O11 case – and an abundance of fans – can replicate or refine the experiment.