The Raspberry Pi 4 now runs cooler thanks to a firmware update

The Raspberry Pi Foundation released its latest single-board computer (SBC) last week to much fanfare. However, the Raspberry Pi 4 runs hot out of the box, with Jean-Luc Aufranc of CNX Software reporting that the SBC would thermal throttle in multi-core threaded benchmarks like 7-Zip.

Well Eben Upton, the CEO of the Pi Foundation, noticed Aufranc's article and provided him with a firmware update with "some thermal optimizations that are not installed by default on early production units". The update addresses the VIA VL805 PCIe USB 3.0 controller, enabling Active-State Power Management (ASPM).

Aufranc reports that the RPI 4 will now run 3-4 °C cooler at idle and under load. He conducted his tests in a room at a constant air temperature too, eliminating that variable from his results. The update, named 0137a8, yields better multi-core performance under sustained load, although some people on the official Raspberry Pi forum have reported a reduction in USB transfer speeds. Moreover, if the update fails for whatever reason, then USB connectivity will break, meaning that you must SSH or serial into your RPI 4 to flash the previous firmware.

You can read Aufranc's test results here or view his lscpi VLI firmware output on Pastebin. The Pi Foundation has posted the firmware update on Google Drive, which you can find through this post.