Enjoy the power while it lasts, but do not build a critical workflow that depends on manually setting this value.
The browser sets browser.cache.memory.capacity to a percentage of total system RAM (e.g., 5–10%), updating dynamically on system changes (e.g., after hibernation, new RAM installed). Browser.cache.memory.capacity
You use an older laptop with only 2 GB of RAM. Firefox’s automatic mode attempts a 16 MB cache, but every tab you open pushes your system into swap memory (using the hard drive as fake RAM), causing the entire OS to freeze. Enjoy the power while it lasts, but do