I hav a mthrbrd with an inbilt VGA crd. i wnt to increse my grafix output,is it btr to gt mor RAM or a VGA crd

i want to increase my comps' performance and want better grafix. my primary concern is grafix, coz if the RAM alone makes a major difference, i wud go 4 that. i just need sum1s opinion b4 spending my money. thnx in advance