Building a Tiny Supercomputer to beat college students

TL;DR

Jeff Geerling builds a DeskPi Super4C Raspberry Pi cluster and benchmarks it against university teams from the SBC Cluster Competition.

Key Points

• 1.The DeskPi Super4C costs $210 and fixes key flaws from its predecessor. It adds an ESP32 for remote node management over Wi-Fi, per-node 2.5 Gbps Ethernet, M.2 NVMe slots, and redundant 19V power inputs — making it a near-ideal compact HPC learning board.
• 2.The cluster achieved 140 gigaflops at ~70 watts, yielding ~2 GFlops/watt efficiency. Thermal throttling initially killed performance until a 120mm fan was placed directly on heatsinks; total build cost with 16GB CM5s runs ~$1,300–$1,400 today.
• 3.Against university teams with a $6,000 budget, the $1,300 cluster landed in the middle of the pack on both performance and efficiency. The NTHU team topped efficiency by underclocking AMD chips and offloading HPL workloads to iGPUs, squeezing far more performance-per-watt from desktop hardware.
• 4.Team Kent Ridge won the overall SBC Cluster Competition using Orange Pi 5 Max boards. Their strategy — maximum RAM, many SBCs, and strong performance across diverse distributed compute tasks — beat pure HPL scores, validating that versatility matters more than a single benchmark.
• 5.SBC clusters can't match a single fast machine for raw value, but that's not the point. The goal is hands-on HPC experimentation; the Super4C is easier to use than the Turing Pi 2, fits in 1U, and costs slightly less — making it well-suited for students learning HPC.