hay, im trying to decide which Video Card is bettr... a Radeon X1900 XT PCI Express 512MB DDR3 Video Card w/DVI-I & VIVO... or a Geforce 7900GT 256MB 256-bit GDDR3 PCI Express x16 Video Card .. I know that the Radeon has 512 mb , but not sure if the 7900 is bettr... let me know plz, thanks!