throttling

Due to a recent surgery, I've been recovering at a location outside my home for a few weeks. I brought all my media with me on a spare hard drive, but one movie I had ripped but never transcoded wouldn't play on the 'Smart' TV here.

It seems to do okay with some H.264 profiles, but not the one for this 4K Blu-Ray rip. Therefore, I thought I'd transcode the file so it would play.

I also wanted to do other work on my laptop—in my lap. And unfortunately for Apple's latest M2 MacBook Air, there's no fan or heat sink to keep the M2 SoC cool.

And that meant the temperature around the top middle of the keyboard—and the bottom middle of the laptop—got quite uncomfortably hot with Handbrake's default settings, which would max out the CPU during the transcoding process.

I could encode anywhere between 10-18 fps at 4K resolution with x264, but the SoC temperature rose to 105°C and was uncomfortably hot within a minute or so.

From home temperature monitoring to a Kubernetes cluster hosting a live Drupal website, I have a lot of experience running Raspberry Pis. I've used every model through the years, and am currently using a mix of A+, 2 model B, and 4 model B Pis.

The 3 model B+ was the first generation that had me concerned more about cooling (the CPU gets hot!), and the Pi 4's slightly increased performance made that problem even more apparent, as most of my heavier projects resulted in CPU throttling. I've written about how the Raspberry Pi 4 needs a fan, and more recently how it might not.

December 2020 Update: Lo and behold, the Pi Foundation tacitly acknowledges the Pi needs a fan in the official case, because now they sell the Case Fan!

The Raspberry Pi Foundation's Pi 4 announcement blog post touted the Pi 4 as providing "PC-like level of performance for most users". The Foundation even offers a Raspberry Pi 4 Desktop Kit.

The desktop kit includes the official Raspberry Pi 4 case, which is an enclosed plastic box with nothing in the way of ventilation.