: Some users disable the disk cache entirely and force everything into memory to ensure no browsing data is written to their physical drive. How to Configure browser.cache.memory.capacity
To get the most out of your memory cache, ensure the following related preferences are also set correctly in about:config : Browser.cache.memory.capacity
Note: If the preference does not exist, right-click any blank area, select , and name it exactly as written above . Enter a Value : : Some users disable the disk cache entirely