In recent Firefox versions (100+), the memory cache is now partially shared with the , blurring the lines between this preference and internal memory management. There is a non-zero chance that Mozilla will lock this value permanently to -1 in future releases, removing manual control.
Increase the capacity to store more assets in RAM, reducing reliance on the slower disk cache. Profile 2: The User on Constrained Hardware Scenario: 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. Browser.cache.memory.capacity
Enjoy the power while it lasts, but do not build a critical workflow that depends on manually setting this value. Conclusion: The Golden Rule of browser.cache.memory.capacity After thousands of words of technical detail, the most important advice is simple: In recent Firefox versions (100+), the memory cache