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# Memory

Purge inactive memory and optimize virtual memory usage

OS X automatically manages the available memory on your Mac to ensure that applications launch and respond quickly. To do this, OS X uses inactive memory to retain shared libraries in memory after an application has quit. The advantage of this is that the next time you launch the application it will load significantly faster, however it also means that the memory is filled with various shared libraries that may not be needed anymore.
Cocktail allows you to free up and optimize the memory usage, which would otherwise require you to reboot the computer. A common scenario where this might be useful is when you are launching a very memory intensive application, such as a virtual machine or photo/video editing software. By optimizing the memory usage before the application starts, it will launch faster and perform better.

Disable virtual memory swapping

This feature lets you disable swapping in OS X. Swapping is a virtual memory technique that allows the computer to use the hard disk as additional RAM memory, allowing the computer to multitask better by giving it essentially unlimited (but slower) memory.
However, there are certain scenarios where swapping can cause problems, for example when it is being used with a solid state drive (SSD). The way that virtual memory is written to the disk can cause significant fragmentation and performance degradation on third party SSDs, in which case it may be useful to disable swapping.
Make sure that you have sufficient RAM installed before disabling swapping as it can cause the computer to run out of memory when running several applications, leading to crashes or other unexpected behavior.

Online information

- Paging / Swapping by Wikipedia.