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.

Believe it or not, the M4 Mac mini was released just over a year ago. Apple changed the footprint, design, and form factor to create a compact 5in x 5in x 2in aluminum box with a fan at the bottom. It ...