hi all new user here. i have a dell gx280 with a 2.8 ht p4. i just got a geforce 7300gs with 256ram and i have 512 mb on board. i tried playing battlefield 2 with new card and i get terrible lag and graphics seem choppy. my question is do i need more ram to be able to play and will that video card require more power than the 250 watt supply that came with this dell?