So you want to change your card to a 450.
Can you tell us your system specs and include Monitor resolution and your PSU make and wattage please.
not to change but want to buy new..other that in the list just bought but not gpu..
AMD Phenom II x4 955 Black Edition
Asus M4A87TD/ USB3 motherboard
Corsair 1333 DDR3 RAM 4GB
WD CAVIAR GREEN 500GB HDD
CORSAIR GS600watt PSU
SAMSUNG 18.5" 1366X768 resolution