Catalyst versions only run with some versions of X and some cards are only provided by some versions of Catalyst. Current "Catalyst doesn't support xorg-server 1.14. Catalyst < 12.10 and Catalyst Legacy do not support xorg-server 1.13. Catalyst < 12.6 doesn't support xorg-server 1.12." - https://wiki.archlinux.org/index.php/AMD_Catalyst#Xorg_repositories This should be equal for Debian.