My main machine at the moment is a Raspberry Pi 4. It's compact and requires only a little power with the downside of being pretty weak computationally and limited by the nature of ARM.
Hardware: Raspberry Pi 4 Model B (8gb RAM)
OS: Manjaro
Desktop: Sway
Running Helix for most text (code and prose), NCSpot, Obsidian (previous mode for my campaign notes). Using Helix with Marksman does most of the things I want from Obsidian besides quickly autofilling relationships (backlinks, etc.), but I am still more comfortable in Obsidian.
The backup machine is an Acer Chromebook Spin 312. I'm a bit of a sucker for ChromeOS and my previous one finally gave up the ghost.