psu/smps for 512mb nvidia gf8400gs pci-e Graphics card

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hi,
my name is rishi. i want to use a 512mb nvidia gf8400gs graphics card through the pci-e x16 slot on the motherboard i have in my pc. my system specs are as follows- core2quad q8200 processor , gigabyte ga-g31m-es2l rev1.1 mobo, seagate barracuda 7200.12 7200rpm 320 gb, 3.5'' sata hdd, 19'' lcd display, 250w no pfc smps- +12v, 15A, 245W max, bios- f9c. please tell me if i can use a 512mb card with this system or if i need to change other things in order to make the system go with the card just fine.