The Most Beautiful Water-Cooled Raspberry Pi 4 Cluster in History

Most computers are air-cooled, either passively or actively with a fan. But water-cooling is occasionally used, particularly when overclocking. Like when Porsche transitioned from air-cooled to water-cooled engines in the 911 line of sports cars, this allows for increased performance by better dissipating waste heat. Even the best machines in the world—computers included — are slightly inefficient, and the byproduct of that inefficiency is often heat. Parts start breaking when they get too hot, so it is necessary to pull that heat away if you want to push the limits of performance. Michael Klements built this Raspberry Pi 4 cluster and it may just have the most beautiful water cooling setup in history.

Every single-board computer in the Raspberry Pi lineup is built to be passively air-cooled. Those computers are equipped with ARM processors that are designed for mobile devices that don’t usually have room for fans. Arm processors are particularly efficient and run on very little power, so the waste heat is minimal. But if you’re constantly maxing out your Raspberry Pi’s processor or if you’re overclocking, then you will want active cooling. A heatsink on the processor combined with a small fan is usually sufficient, but water cooling is even better. It is superior because heat transfers quickly from the heatsink to the water, which is then pumped away to a massive heatsink and fan. That’s probably overkill for a single Raspberry Pi, but it is great for a cluster like this one.

This cluster contains eight Raspberry Pi 4 Model B (2GB) computers that can work together to process distributed loads. They’re all cooled by an off-the-shelf water cooler system that was modified for this build. That has eight heat blocks that are attached to their respective Pis in series with laser-cut translucent red acrylic mounts. Cooling in series does mean that the last Pi in the chain will get the warmest water, but it should still be effective in this case. Power comes from a beefy power supply via USB. To ensure network throughput and reliability, the Pis are connected via Ethernet to a switch. A 7” touchscreen LCD is connected to the master Raspberry Pi node to display data about the current job and each Pi’s status. All of those components are mounted onto a large wood frame that was painted black. A strip of LEDs behind the frame creates a nice glow effect. Klements doesn’t go into the software side of this project, but the hardware alone is stunning to look at.