To prelink all files after installation:
# prelink -amfR
(can take some time. use v for verbose output)

After every new installation, you must update prelink.
prelink the installed files by hand or run:
# prelink -amR

To unprelink all files, before you remove prelink:
# prelink -au

To speed up KDE with prelink, set 
KDE_IS_PRELINKED=true
Do this before you start KDE, maybe in /usr/bin/startkde