I have been using KDE as my window manager for nearly as long as I have been using Linux as a desktop environment. I have looked at Gnome - very briefly, on a Solaris machine - and hated it and never expected to change.
KDE is resource hungry, and I have always known this. An extremely elderly ThinkPad that serves as a terminal in the kitchen has always run TWM, as KDE would have just ground it to a halt. My old and much-repaired Toshiba laptop was also on its way to grinding to a halt so, when I had cause to do a clean re-installation (Gentoo), I looked at alternatives and came up with Fluxbox. I really could not believe how much faster the system ran with Fluxbox, compared with KDE.
Following my initial success, a re-installation of the ThinkPad (Debian) included replacing TWM (yuck) with Fluxbox. Another success!
Having then put Fluxbox on my Sun Blade (which rarely runs X), I was left with just my main server/desktop machine running KDE. I knew that the performance of this machine could do with a boost - KDE utilised a lot of resources that the mail and Web server software could have done with. Having just configured KDE to launch applications from a right mouse click to emulate Fluxbox on other machines, I had to ask myself exactly why I needed KDE.
Konsole, Konqueror and KWorldClock. Three KDE applications that I would rather not live without. That is why I need KDE. And that is where I had been confused. One does not need the KDE desktop to run KDE applications. For the last hour, I have been running Fluxbox on what was the last bastion of KDE - and quite happily using Konsole, Konqueror and KWorldClock. Although those applications all cause a large number of KDE processes to run, when terminated, those processes go away, wasting memory and CPU cycles no more. Things are looking up.
Smiffy at LinkedIn