Thanks for the advice .. I think I'll buy Asus GeForce GTX 650 Ti DirectCU ii Boost OC 2GB GDDR5 ..
I installed the drivers directly from AMD's website..Then it would be something like this ... Right?
I dont know how you usually install drivers, but normally you would uninstall the old ones first and switch to mesa before you add a new card.
1-Uninstall proprietary drivers from ATI/AMD and reinstall mesa.
2-Turn off the computer , open the box and put the new graphics card.
sudo apt-get remove --purge xorg-driver-fglrx fglrx*
sudo apt-get install --reinstall libgl1-mesa-glx:amd64 libgl1-mesa-dri:amd64 libgl1-mesa-glx:i386 libgl1-mesa-dri:i386 xserver-xorg-core
sudo dpkg-reconfigure xserver-xorg
4- Upgrade the system: Going to additional drivers and install proprietary drivers from my new graphic card....