I am having the computer system and i want to purchase the new graphic card for my computer system as the system currently has the onboard graphic solution. I want to attach the 512MB graphic card. I am confused between the two ATI graphic cards and not able to select anyone from them. I have selected the XFX ATI Radeon HD 4650 and ATI Radeon 9800 pro graphic cards. Help me out in selecting one graphic card from these two.