dunno, it may not have been a kde specific article, could have been linux in general. i remember, in short, it said something like; kde/or linux uses 90%-100% of physcial memory, cause good ram is ram put to use, if physical memory is not used for applications it's used for disk cache and freed up when needed. something like that. and indeed when i run ksysguard in kubuntu my physical memory is used to 90-100%, swap very rarely used. i have 1gb of ram.