The preference is a hidden setting in Firefox's about:config that controls the maximum amount of RAM allocated for the browser's memory cache.
Ensure browser.cache.memory.enable is set to for this to take effect. Why Adjust This Setting? Browser.cache.memory.capacity
Completely turns off memory caching. Not recommended as it slows down browsing significantly. Positive Integer Manual Limit Sets a fixed limit in kilobytes (KB) 3. Recommended Manual Settings The preference is a hidden setting in Firefox's
The setting browser.cache.memory.capacity is a "hidden" configuration in Mozilla Firefox Browser.cache.memory.capacity
