So, I have one of my machine which has 1GB RAM... I know it is good enough for the work I do, but still being that fanatic of getting more RAM for my work, I did the following changes to increase the free RAM.
1. Disable unnecessary services. There are two places this needs to be done as some services use upstart and other are still using init.
2. Disable upstart processes. Browse to /etc/init and rename the files ending .conf to something else and that service would not start. Remember not all services should be disabled.
This is the screen shot of the services I have disabled. I have appended a ".no" to the file name.
3. Next is to install the software sysv-rc-conf.
Run it as root in a terminal and remove the check marks for those services which you do not need.
I generally remove bluetooth, blrtty, portmap, samba. Do not remove
bluetooth - if you are going to use bluetooth on your computer.
blrtty - if you are going to use the assistive technology features of the OS.
portmap - if you have done any port mapping on the computer.
samba - if you are going to share using samba with some windows computer.
After doing this, my memory consumption in KDE4 is 198 MB... went down from some 300MB odd which was earlier. Suprisingly, KDE4 is taking lot less memory compared to gnome. May be the new GDM is taking lot of memory.
I keep shuttling between KDE and Gnome from time to time, but off late have been using KDE4 for its widgets and cool features.