Is a premium aluminum case worth the investment? We compared standard injection-molded plastic cases against our CNC-milled 6061-T6 aluminum enclosures.
Thermal Conductivity 101
Aluminum has a thermal conductivity of ~205 W/m·K. Plastic (ABS) is roughly 0.17 W/m·K. That is a 1200x difference in heat transfer efficiency.
The Results
In a 25°C ambient room, the plastic-cased Pi 4 throttled within 8 minutes of stress testing. The MILL & GRAIN CNC case maintained a steady 42°C for over 2 hours. The choice is clear for anyone running mission-critical workloads.