geforce6500

hi have intel 2.8gz(hyperthreading) processor and intel 915 gav orignal motherboard,512 m.b ram,80 gb sata segate hdd. i want to buy a graphic card and i have been offered a XFX geforce6500 card 256 mb ddr2 for 4200/- .is it better than my onboard intel extreme graphics.is it worth it.