Virtual Memory swapfiles and OS X performance

A. Brody has updated his Mac OS X Installation FAQ to include information about how too little free hard disk space (often combined with too little physical RAM!) can lead to insufficient space for virtual memory's swapfile, leading to performance slow downs. This is something we first noted back in the OS X Public Beta (see this item). The FAQ explains how you can check if this is happening to you.

On a related note, ResExcellence has a new tutorial titled "Using a Dedicated Swapfile Partition to Speed Up Mac OS X." It notes: "Unlike most other UNIX versions, Mac OS X does not use a separate partition for the virtual memory swap file. This article walks you through creating a swapfile partition which will cut down on hard disk thrashing and speed system performance.

Update: Another tutorial on moving swapfiles was covered in this MacFixIt Forums thread (Easiest method to move swapfiles!). The author, Mike Bombich, also covers it on his web page.

We have also previously mentioned another thread (Need help setting up a swap partition) and web page on this topic.