Firefox: Swap out to disk memory when minimized

Swap out to disk memory when minimized (Windows only)
A little-known feature in Firefox allows the Windows memory manager to swap out some of Firefox's physical memory space to disk when Firefox is minimized but not closed. This allows other programs to use the physical memory that Firefox was previously monopolizing.

Firefox's minimized memory usage with (top) and without (bottom) config.trim_on_minimize. (Click for larger view.)

By default, this feature is turned off, for two reasons: 1) PC memory is generally more plentiful than it used to be, so it makes sense to use it if it's available, and 2) swapping Firefox's memory out to disk will slow the program down when it's restored.

That said, if you run Firefox side by side with other memory-hungry applications, it might help keep them from competing with each other. To enable this feature, create a new Boolean preference called config.trim_on_minimize and set its value to true.