'When the Raspberry Pi 400 (a keyboard form-factor single board computer) was released last week, the company hinted at overclocking. Testing has now shown that the heat spreader used in that design does an excellent job. The chip was already clocked at 1.8 GHz, versus the stock 1.5 GHz in the original Raspberry Pi 4 Model B board. But it can be safely overclocked to 2.15 GHz, as can the Compute Module 4 with an adequate heat sink. At 2.0 GHz, the Pi 400 got up above 60 C and showed signs of continuing to warm up even after 50 minutes, but it was nowhere near throttling. So I tried 2.2 GHz, at which speed the CPU refused to boot entirely. Backing down to 2.15 GHz, it ran just fine, so I left it for three hours. It settled in at a cozy 62.5 C, which is warm, but well within specs. I ran the CM4 with the larger heatsink at 1.8 GHz to give some basis for comparison to the cheap heatsinks. What a big difference a big hunk of aluminum makes! It settled in at a comfortable 68 C or so. Even pushing it up to 2.15 GHz and leaving it for a couple hours, it stayed just a hair below 70C (158F) -- a safe margin on the throttling threshold -- and only a few degrees warmer than that huge heat spreader in the Pi 400.' -- source: https://hardware.slashdot.org/story/20/11/11/182203 Cheers, Peter -- Peter Reutemann Dept. of Computer Science University of Waikato, NZ +64 (7) 577-5304 http://www.cms.waikato.ac.nz/~fracpete/ http://www.data-mining.co.nz/