microsoft research principal researcher ofer dekel penned a recent blog post that offered a solution to a raspberry pi overheating when being pushed to its limits during intensive workloads, specifically related to artificial intelligence.

the cooling solution devised by microsoft for the raspberry pi.
(microsoft research)

dekel showed that the raspberry pi processor heats up more than other components on the board when running a compute-intensive ai model, so he gives a tutorial on building an active cooling solution to ensure the processor runs reliably.

the materials that dekel recommended were:

• adafruit aluminum heat sink for raspberry pi 3 - 15 x 15 x 15mm (comes with a thermally conductive sticker), or equivalent.
• adafruit miniature 5v cooling fan for raspberry pi (comes with mouting screws and nuts), or equivalent 5v 0.2a dc brushless fan, 30mm x 30mm, with mounting holes spaced 24mm apart.
• the secret ingredient: our pi 3 fan mount. you need to 3d print this part.
• two m2.5 x 12 pan head machine screws and nuts, to attach the fan mount to the circuit board.

read the full article at https://microsoft.github.io/ell/tutorials/active-cooling-your-raspberry-pi-3 to see all the steps to building an active cooling solution.

dekel also addressed the idea that the processor could be cooled with only a heat sink. microsoft ran an experiment by running all four cores of the pi at once using no cooling solution, a heat sink on the processor but no fan, a fan without a heat sink, and the recommended solution of a mounted fan and a heat sink.

“the none configuration quickly overheats,” dekel wrote. “within a few minutes, the processor temperature hits 85 degrees, the temperature at which the processor starts protecting itself by throttling down its frequency. the passive cooling configuration, heat sink, isn’t much better. at first, the heat sink absorbs some of the heat, causing the processor temperature to rise more slowly.

“however, the heat sink struggles to dissipate that heat and the processor temperature gradually climbs into the 70s. the passive heat sink prevented the processor from reaching the critical temperature of 85 degrees, but came too close for comfort. processor temperature depends on many factors, such as ambient temperature, processor load, and processor frequency. moreover, different raspberry pi units behave differently. the experiment was conducted in an air-conditioned office (room temperature was about 26 degrees celsius) and we can imagine getting into trouble under different circumstances.”

the fan solution kept the temperature level at 63 degrees, but the best solution was the fan and heat sink combination, which kept the processor running below 50 degrees.