If you prefer open source drivers on your setup which became necessary after GDM issue with fglrx follow the steps below.
equo install xf86-video-ati
edit sabayon-grub
nano /etc/default/sabayon-grub
make sure the lines below are removed
console = tty1, quiet splash = **** and vga = ****
edit grub
nano /etc/default/grub
make sure nomodeset is not defined anywhere
Regenerate grub.cfg
grub2-mkconfig -o /boot/grub/grub.cfg
Edit and make necessary changes on xorg.conf
nano /etc/X11/xorg.conf
add the following lines
Section "Device"
VendorName "ATI"
Identifier "X700OS"
Driver "radeon"
EndSection
Change opengl setting if not yet.
eselect opengl set xorg-x11
