In a surprise move, the M4 Mac mini includes a removable, swappable SSD. Apple really should give customers the option to buy high-capacity versions of these as storage upgrades for the tiny desktop.

The M4 Mac mini came with a surprise — a slotted and upgradeable SSD. Here's how to install one, get it running, what to expect for speed, and what's happened in the last eight months since upgrading.