Ubuntu Unleashed

Here I will provide you with some information to help you decide exactly how you would like to tweak your system. I have seen many sites with the swappiness tweak for linux without any documentation on what it does, so I'll try my best to explain this in a simple way.

If you want linux to use as little memory as possible for caching files, and as much memory as possible for processes, and only swap when the memory used by processes is more than the physical memory set swappiness to 0, instead of 60. Users who would like to never see application memory swapped out can set swappiness to zero. This setting uses ram efficently and pretty much ignores using swap until it absolutely needs to like if your running 10 openoffice's and a few firefox windows and some multimedia applications, it will be forced to swap, thats the only way it will. Unfortunately it flushes the applications from memory when you load a new one so you will notice a slower restart time when reloading the application

If you run allot of memory intensive applications like firefox, amarok, and openoffice all the time, you may want to set swappiness to 100 because it will swap more to disk when your current processes run out of physical memory. I noticed that everything was a bit more responsive with this running many programs at once, like when I close firefox and load up xChat then re-open firefox, it loaded a bit quicker since it was swapped. You can take advantage of this setting if you have a fast extra hard drive or a fast usb flash drive which you can use as swap. I have provided a readyboost for linux howto here

Lets get to tweak'n
sudo gedit /etc/sysctl.conf
To disable swapping application memory add the line:
vm.swappiness=0
To Swap more application data to disk when ram is exhausted
vm.swappiness=100

Basically what I would do is experiment with this setting and see what works best when you load up plenty of applications you use daily because leaving it at the default, 0, or 100 may not be the best option.

Please let us all know your specs and what setting works best for you.